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The following are collection reviews from the MCS team members for your reference. Shall there be any query in regards to the review(s), kindly contact the team member(s) for clarification.

How to Read British Standards (BS)

posted May 10, 2022, 6:23 PM by jeffery jim   [ updated May 10, 2022, 6:27 PM ]

I spent the whole afternoon drilling my proteges about all parts of BS1377. It is hard to read BS continuously and during my varsity years, I can hardly read more than 2 to 3 pages in one seating. Most of the time, I will doze off and that made it almost impossible to understand things and pass design subjects.

2. The thing about BS is its nature which goes in point format and dull, unlike American codes which usually in paragraphs and narratives for clearer understanding. Eurocodes are much easier to read as they are in paragraphs with better narrative(s). Nevertheless, every engineer needs to understand the fundamental concepts and rely on these in order to perform their duties or to utilize exploits that are available in it.

 3. The right way of understanding the concept in BS or parts of BS is to understand the normative references and assigned parts. Second, read through the table of content and comprehend the coverage of the standard and core concept on each main item.

4. Mind mapping is essential unless you have a good photographic memory that links each part and concept to another. Understand the similarities, alternatives, and differences.

5. Start with a general concept or the primary standard before moving to other normative references. One have to read in the light of another documents in order to render the actual concept and approaches. Without normative references, one can be handicap and have their mind mapping links truncated. This is not a good process when working around BS.

6. Read one main item or one specific proceeding (can be a test or key concept) in each sitting. Do not push yourself to read more than what you can take. It is much easier to understand things within the above-mentioned limit nowadays. Finish each sitting by watching two to three Youtube videos that are related to your reading. This will reinforce the concept with audiovisual aid. At the same time, this will assist you in comprehension if English is not your first language.

7. Revisit your reading in a week or a month's time. Try to read and visualize what is/are mentioned in each passage. Reading buddy would be great where a pair can go for a spar by asking related questions based on videos or relevant BS. Jolt back everything you missed in your mind map(s). Now you have a comprehensive note on the subject(s) that matters.

 I hope you can benefit from this tip when you are trying to learn via BS independently. One day, you could duplicate what I am able to do, which is to make references to standards without stuttering and in a convincing manner

Pile Integrity Test

posted May 8, 2022, 6:07 PM by jeffery jim   [ updated May 8, 2022, 6:08 PM ]

This is a very informative video about Low Strain Impact Integrity Test although there are several (5 types to be exact based on ASTM). Out of these five, most time we will utilize two specific types of test which are High Strain Impact or PDA and Crosshole Sonic Logging. I prefer both of these tests than the rest. The followings are addendum about this video which one can benefit when monitoring bored pile or casted pile at site.

Pile Driving Analyzer (PDA) displays the same wave as per low strain in the graph in order to check pile's integrity and/or impedance. For starters, impedance of a pile can be defined as follows. "Change in impedance is related to change in pile cross-sectional area A, as well as pile material quality. Increase in pile impedance or soil resistance forces results in a decrease in measured pile top velocity. Conversely, decrease in pile impedance, results in increased velocity. By observing changes in impedance, pile quality."

In the same manner, we can check necking or bulging/bulb that may occur during boring and casting thru PDA. It is important to check CAPWAP graphs and not rely heavily on summary of the Integrity Class and Acceptability as well as the CAPWAP capacity which is the estimation for both end bearing and skin friction. Nevertheless, it is usually the case when specialist review the classification based on graphs but with some common knowledge about wave(s) propagation, one can crosscheck the work of the specialist signing off that particular test record. I encountered a few cases where the graph is not satisfactorily conform with high integrity rating which I will not discuss here.

The benefit of using low strain compare to high strain is the accessibility and mobility of conducting test on completed sections. Second, it is the only way to have some initial assessments on the shape without the need of tubular pipes for Sonic Logging Test and when Bi-directional Static Load Test (BDSLT) or Static Load Test (SLT) failed the three criteria or a single criterium for working load settlement, twice working load settlement or residual settlement.

The second test would be Sonic Logging (USPIT). This particular test compliment what was discovered in in PDA test. This test is conducted prior to the execution of PDA test where the shape and integrity of the pile is examined through cross sections. The larger the pile, the more sections are required, similar to low strain PIT using echo and receiver. Based on this waterfall wave and spectrum, one can determine the existence of honeycomb and other irregularities such as necking and bulging of pile.

The importance of the shape not only crucial in ensuring the integrity of pile especially when there are possibility of necking. Bulging or bulb is not really crucial as it increases skin friction and overall pile capacity; however additional load may be substantially dangerous for the total load at the bearing and/or skin friction. Additional load from bulging of the casted pile can be detected when conducting BDSLT and not in Static Load Test. The reading of the top side of the O-cell or jack will indicate that when compared to bottom side of the jack. This is one of many ways to vindicate or justify when BDSLT reading may deviate aside from soil strata/stratum change(s). This serves as complimentary observation(s) when checking/diagnosing pile or piles' performance holistically.

There are so many variables when estimating pile's capacity and performance. I reckon that sound regional or local geological understanding plays a very high significance for a site engineer or resident engineer to plan for total depth and the inclusion of proper socketing length. In most cases, I rarely follow recommendations made in the drawing if the soil at the boring point have low performance despite the depth set by the designer. With sound and clear estimation, we rarely find issues with working load settlement and residual settlement. In most cases, the issue will only occur with twice working load. Why? The base of the bored pile was not cleaned totally, hence it requires certain degree of depth to mobilize the end bearing.

Low Strain Pile Integrity Test

What triggered such cracks?

posted May 8, 2022, 6:05 PM by jeffery jim

I saw this article and it is quite intriguing where some comments which were made by readers are controversial. Whose fault is it when there are such cracks grazing around the end of the beam? Is it the contractor, consultant or client?

2. Most of the comment made directed such structural failure to consultant. It is definitely convenient as it renders a perspective where cracks triggered when there is lack of reinforcement bar (stirrup or nominal links) at the said area. This led to the reaction of beam(s) under duress and sheared under loads (sic). This is most probable scenario for most structural engineers when they look at this particular photo in the first place. Is it really the case?

3. Typically, such crack patterns are related to shearing but it is hard to establish it is the outcome solely due to the reinforcement issue. There are other issues that one must consider before ultimately putting such failure as design failure.

4. Causal and outcome should be listed as possible mechanisms which trigger such crack. In this case there are several.

4A. Post Tensioning. The construction of such bridge utilizes a lot construction methodologies in post tensioning fabrication in comparison to typical in-situ short span bridge. In this case, usually tendons take precedence when talking about beam performance before the reinforcements. In this type of construction, tendon profile is essential and depends on the end of both tendons. If both ends are live end, then that is not an issue. Nevertheless, if one dead end, this should be visible when stressing is conducted. Failure during stressing where displacement exceed 6% should indicate the failure of tendon or the anchorage bulb (spiral).

4B. Another factor one should consider is the concrete characteristic strength and reaction during the curing period. Low concrete strength will have very low performance for most engineering properties. Second, the hydration and formation of ettringite which may trigger cracking when Delayed Ettringite Formation (DEF) occurs due to exposure of concrete under high heat and inappropriate curing procedure.

4C. The third possibility is the formation of alkali-silica reaction (ASR) or alkali-carbonate reaction (ACR). The low maturity aggregates maybe susceptible to chemical reaction and lead to crack formation. This incident is the initial mechanism which leads to cracks propagation and not the main reason for such failure to occur.

5. There are several other reasons which may propagate or trigger such crack but degradation in the long run. If we put all of these into a desktop study, it pointed all three parties; consultant, contractor and client as defaulting parties. Contractor might have failed to diligently check their work before commencing to another stage. The consultant have failed to supervised the job with low workmanship or failed to interpret test records and reports. Client? Yes. In this case, the client can be blamed if they failed to stipulate or mentioned about the suitability of materials in their specification and allows recommended material (in this case, aggregate) which is highly reactive to be used as construction material.

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Is this something one must consider when constructing a pool beside a residential property?

posted May 8, 2022, 6:04 PM by jeffery jim

The answer is partially true and depends on the ground condition. As a professional engineer, I am less worry about the foundation. I am worry about the swimming pool instead. Let me explain.

The reason why it is highlighted that an excavation can trigger settlement or partial settlement to the property is due to bearing capacity of the soil. For those who understand geotechnical engineering, settlement issue is less likely to occur in most commercial properties in Malaysia. Most properties are resting on piles and hence there will be slight reduction for skin friction of the pile. In case the property is sitting on end bearing pile, this is less likely to be a worry at all. Issue about lack of soil and even overhanging pile will not be an issue.

For civil engineers with clear conscience, the real issue here is the swimming pool. If the property (single storey) is resting on pad footing, the bearing is a major concern as it carries and distribute load accordingly to the ground and not to bearing (harder ground). Assuming that the standard design is 100kPa, which is around 10 tons per meter square. The allowed imposed load or quasi permanent load will be able to perform accordingly since this particular load may only be around 2,500kg per meter square. This factor is more than sufficient.

In most constructions, soil treatment is one way to go forward for soil with extreme ground condition. Usually, excavation will take place until the depth of 3.0 meter. Geotextile (separator) is placed before backfill with suitable material. In this condition, the bearing would reach until 100kPa. How about soil strata below the treated zone? Say, it reaches 30kPa for peat or organic soil. What will happen in the long run? In this case, it reaches equilibrium where the soil's bearing is just sufficient to carry the quasi permanent load of the water.

The issue will arise when it comes to long run operation. Organic soil have high degree of compressibility as voids will fill the space and the reduction of water table. One only can forecast this state of settlement via Oedometer testing. In some instances, certain soils may reached 300mm settlement over a period of a month. Changes due to settlement can create issues.

1. Differential settlement which is triggered by different rate of settlement will lead to cracks to the swimming pool. This will further aggravate the situation if cracks of more than 0.3mm formed and water seepage is expected. When water seepage occurs, propagation of cracks will happen and cause uplifting and bulging. Areas which are not affected will remain or continue to settle and tilt depending on the rigidity of the swimming pool structure.

2. Water discharged and infiltration will lead to the weakening of the property's bearing. If the property is sitting on piles, then infrastructures such as stormwater drainage and sewer pipes could be deformed over a period of time. If the property is sitting on pad footing over the treated soil, the problem will be dreadful and could be hazardous. Similar to the swimming pool, the property resting of pad footing will start to experience differential settlement and over a period of time, this will trigger superficial cracks on architectural elements and it is matter of time before cracks start to plague on structural elements.

3. Only through Triaxial testing, one can only define the right diagnosis before coming out with the right remedial works. The outcome is similar to properties which experience industrial dewatering or trenching work parallel to the affected properties.

Therefore, it is less worrying when talking about an imaginary 45 degree isobar since this is not fully true and depends on the soil types which sits as bearing for property's pad footing since this may change the actual contour of the isobar. It is advisable that swimming pool issues should be first tackled or addressed before considering issues related to isobar and differential settlement which may affect the integrity of the property.



posted May 8, 2022, 6:02 PM by jeffery jim

Extension of Time (EOT) in construction industry is an added time which was granted by the Client after scrutinizing incidents which have contributed directly and require extended time for the contractor to complete a project with or without variation to the contract price. There are several prerequisite criteria which a contractor must conform in order to be grated EOT and in certain projects, EOT can be granted multiple of time. In my past project, Client (Oil & Gas MNC) have to award me one and a half year EOT, however granted me only six months due to other constraints which I will not name here.

2. Planning is divided into two criteria; technical project planning and tactical project planning. Both of these use similar software such as Microsoft Project and Primavera but the approach used in dictating a project is different. Technical planning usually revolves around compliance in updating and reporting about the current progress with the assistance of other diagnostic tools and the use of Monte Carlo simulation. Tactical project planning is another level of technical planning where it embodies the contract and risk as precedence before other elements in technical planning. Moreover, a lot of other analyses involving contract and risk will take place. Contract interpretation involves the contract document and other legal elements, while risk mitigation involves more than just Monte Carlo simulation. This includes statistics such as Pearson or Spearman correlation, time-related binomial distribution and utilizing Latin Hypercube Sampling in order to provide level of significance for event(s).

3. Once EOT is granted, a project planner will have to do the followings;

3A. To update all activities with appropriate progress percentage before making current progress at site as a basis or baseline. All existing baseline dates. durations and costs can be transferred to Baseline 1. Subsequently, a new baseline dates, durations and costs shall be established in accordance to awarded new completion time and cost. In certain cases where omission is required, cost adjustment or realization will take place to reflect the new instruction and notice(s).

3B. To recalculate remaining works using productivity schedule for affected activities and group these dates as optimistic duration, mean duration (from your planning software) and pessimistic duration. In this particular calculation, additional considerations should be included in case possible delay(s) may be prolonged. SWOT analysis can be handy but a planner must ensure that quality and cost should not be hindrances to achieve targeted duration.

3C. If there are additional works to the EOT as in variation to contract price, additional works should be included in the new work program with approved cost. This should be introduced with new task relationship(s) that may see existing tasks to shift forward into a newer completion date. One of the biggest failures many did previously is the failure to leverage the resources. Introduction of newer activities and extended time do not mean a project is able to employ and discharge workers based on the man-month. One have to review their resources histogram and their financial momentum. In no way, a project should be allowing sudden dip or spike to their monthly expenses. I reckon the S-curve to be as linear as possible to avoid disastrous outcome for additional project funding and additional cost contributed for financial interest when cashflow is running below optimized level.

3D. After completing the new proposed baseline, a sequential analyses can be performed to see if the new work program is robust enough to tackle all contractual issues if one wants to established dominance in tactical planning and robust final account. The additional works or delayed work may render as critical path but in certain cases where multiple elements was considered, this may not be the case. For this purpose, always try to gauge and foresee possibilities of delay that maybe triggered by contract sub-clauses (in Malaysia case PWD203 and its variants - Extension of Time, and Loss and Expenses).

3E. The outcome of analyses would indicate how robust the work program can be and is bulletproof from contractual elements. When satisfied, this shall be submitted as a new work program and use for scheduling purposes. Else, it is back to the planning board for continuous rework.

4. In this particular write up, the complimentary information on tactical planning is the ability of a planner to exploit contract clauses but one have to be very articulate when it comes to causal and sequential route to the utilization of such exploit(s). I hope project planners are aware of their responsibilities and articulate their depth of knowledge in contractual and legal matters into the work program. Planning requires wisdom or else, a planner is just a scheduler or an operator.

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BS EN 1504: Product and Systems for the Protection and Repair of Concrete Structures (Part 2)

posted May 8, 2022, 6:00 PM by jeffery jim

In my previous article, I wrote about the introduction to BS EN 1504 and the two categories of principals which involve concrete (Principal 1 to 6) and reinforcement bars (Principal 7 to 11). The followings are details about each principal for better understanding when selecting the appropriate prognosis based on analyses conducted from diagnostic procedures.

Principal 1: Protection against aggressive substance. This principals highlights the need to have proper protection against aggressive substances or substrates such as chloride from seawater, chlorine from swimming pool, gasses in factories and corrosive environment, and other chemicals from direct physical contact. Substantial cracks allow these substances to infiltrate and existing pores from high water cement ratio and hydration process will allow deeper penetration and reduce the durability of the concrete by lowering its passivity.

Principal 2: Moisture control of concrete. Concrete with high moisture content have high potential to trigger corrosion. There are different states of water (H20) which leads to a chain of redox reaction when in contact with reinforcement bar. Other detrimental substrates will aggravate the whole condition and work as catalyst(s) in my many forms in many states, as gas, liquid, aqueous, and/or hydrate (solid).

Principal 3: Replacement of damaged concrete. When concrete has lost its integrity in certain section or part of structural members, the affected section shall be replaced by newer concrete. Replacement will allow partial rejuvenation and reinstates its initial intended purpose from further degradation.

Principal 4: Strengthening of building component. Under extreme condition where concrete degradation will affect its overall performance in a larger section of master or slave structural system, strengthening is required by introducing new components through retrofitting.

Principal 5: Improvement of the physical resistance of concrete. Unlike replacement and strengthening principals, this principal is not limited to overall integrity and strength. It is a way to introduce preliminary barrier or jacket against element and physical attack/ingression and retain the durability of the concrete.

Principal 6: Improvement of Chemical Resistance. This principal have similar intention as per Principal 5 but with specific intention(s) to create or increase durability from aggressive chemical attack.

Principal 7: Restoring reinforcement passivity. Principal 7 is designed to preserve the reinforcement bars from corrosion when concrete is infiltrated by detrimental agents and lost its passivity. The introduction or enhancement of barrier such as covers and actions to re-alkalized the concrete and reinstate its cover and infill passive state.

Principal 8: Increase of the electric resistivity of concrete. Electric resistivity is a property which retards the potential for current or charges formed by anode and cathode for the same reinforcement bars or adjacent reinforcement bars.

Principal 9: Control of cathodic areas of the reinforcement. Before current flow induces the movement of electrons, this principal will take the prevention step from forming anodic reaction and reduce the potentials of corrosion of the reinforcement bars.

Principal 10: Cathodic protection of reinforcement. When corrosion occurred and yet to be extensive, methods are introduced to suppress the potential of corrosion at anodic areas of the reinforcement. This principal approved both active and passive systems.

Principal 11: Control of anodic areas of reinforcement. Another method of suppressing corrosion is by tackling the anodic area instead of cathodic areas as per Principal 9. Most of the time, a sacrificial element and/or films are introduced using material based on its range of metal nobility.

Therefore, with these principals, engineers and/or technologists can choose appropriate principal(s) and financially optimized method(s) specifically for localized defects and holistically, structural integrity. The right methodology of repair, rejuvenation and rehabilitation would enable the structure to prolong its intended lifespan.

May be a close-up

BS EN 1504: Product and Systems for the Protection and Repair of Concrete Structures (Part 1)

posted May 8, 2022, 5:59 PM by jeffery jim

Reinforced concrete structures are one of the most durable and robust structures around us where cement and concrete history can be traced to early civilizations. Cementitious compounds or substrates have been use as mortar for the Great Wall of China and other structures in early Chinese civilization. The Romans initiated the use of concrete for superstructures before the Chinese and specialized in marine concrete which can set underwater. The use of concrete among the Greeks are less prolific than the Romans. Modern day cement was invented in 1824 by Joseph Aspadin and this cement is known as Portland cement.

2. Although it is generally accepted that concrete is robust and durable, the main issue with the use of reinforced concrete for construction is the susceptibility of reinforcement bars in reinforced concrete to corrosion. When concrete lost its passivity in several ways and due to the ingression of detrimental elements, reinforcement bars will start to corrode. The reduction of surface area and pitting will result in reduction of overall tensile strength. Therefore, reinforced concrete structures will always have a thin layer called "cover" which will protect reinforcement bars and concrete infill.

3. Concrete structures are similar to other structures made of wood, steel and aluminum where degradation will take place after some time. Thus, in most design literatures, limits are set and typically categorized as serviceable limit and ultimate limit. When a structure about to lapse its serviceable limit; rehabilitation, rejuvenation and repair is/are required. For reinforced concrete structures, the guideline to conduct such remedial works are based on BS EN 1504 with 10 parts which highlight 11 principles and various methods. One have to understand that these 10 parts do not exclusively tied to the 11 principals but relevant to methods.

4. BS EN 1504 may have the list of remedies for concrete repairs and rehabilitations, however the outcome of selecting the right principals and methods rely heavily on prognosis and performed diagnoses. In certain instances, diagnoses and prognosis may not resolve to the use of solution(s) provided in BS EN 1504. Hence, a professional engineer or technologist has to recognize the actual scenario and may make normative referencing to other specifications.

It is certainly a rare case when issues are not detectable through procedures as prescribed in BS/MS EN 13791, BS EN 12390 and MS1242. Misleading and oversimplified methodologies and tools for diagnosis are often the root cause of incomplete prognosis. This can only be tackled through statistical analysis as I reckoned in my recommendations to JKR practice through multivariate statistical analysis (DOI: 10.1088/1757-899X/1229/1/012003). In this particular journal article, my case study indicates the actual culprit in diminished concrete strength which can only be detected through Scanning Electron Microscope (SEM) Petrography and X-ray diffractometers.

5. When prognosis directs the utilization of the right solution for the use of extending the structure lifespan, method should be determined based on the principal(s) and the application should comply with BS EN 1504.
Similar method could reappear in different principals and this can provide more than a single purpose when applied. Principals are divided into two categories; protection of concrete and protection of reinforcement bars. A method may provide protection for both in some instances. Principal 1 to Principal 6 protect the concrete and Principal 7 to Principal 11 protect the reinforcement bars.

(To be continued)

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RM50,000 Jetty - Why not concrete?

posted May 8, 2022, 5:53 PM by jeffery jim

I get this kind of question early in the morning. Well, I can explain it easily to those who are eager to learn and not make judgment like every learned people. Why don't JKR Sarawak use concrete instead as this is a cheaper option?

2. For those who are not familiar with construction, they may not know properties of this particular wood as we are now living in an era with soft wood being use for our furniture. It is understandable why many feels that this is an overspending exercise and to certain extend thought there is a misconduct or misappropriation by certain parties. Let me guide you to understand things that are factual.

3. Wood properties. As I have mentioned yesterday, Belian or Ironwood is categorized as S.G. 2 in wood group and considered as very hard wood. This particular wood is durable and comes with good engineering properties which people often forgotten. It is harder than most wood and have no problem to be used as scaffolding access, walkway and working platform.

4. Durability and susceptibility to attacks. Belian in one of the best woods when it comes to exposure to marine, especially borer bugs that infested riverine and estuaries. Hence, this provides better durability than concrete. If we look at the site and its remoteness in logistics, it is one of the best construction option available. Then this particular grain properties which is great against shear and other load-related exposure. Unlike reinforced concrete which highly dependent on reinforcement bars when it comes to tensile load.

5. Concrete is not as good as Belian. Commercial premixed concrete is not a good option for this kind of construction since most of these type of concrete are not specially designed with trial mix conducted. If one is familiar with concrete specification, typically a concrete will start to stiffen after 40 minutes and that is why concrete cold joints are permitted for work under 45 minutes with exception of trial mix extended to 3 hours like how we do it in Pan Borneo with proper documentation of retarding properties and procedures to ensure concrete is not stiffen and cause low workability. Imagine those hours required for a concrete mixer to transport heavy load through undulating and plantation road with high gradient. Dosing using water to increase workability is not permissible as this will increase water cement ratio and further reduce concrete durability.

Apart from that, lower grade concrete such as G30N have very high cement water ratio. This issue is a durability issue which was going to and fro for many years in concrete technology. For this particular matter, revisions of concrete durability from CP110 to BS8110 (several revision for Part 1) and Eurocodes have tried to fix this issues and is still a matter for debate. Now, this answers why substructures previously are required and additional 5kN/m2 to 10kN/m2 for foundation than the actual characteristic strength for the structure.

After hydration, CSH gel will form and microcrystalline will leave voids which make concrete very fragile against the ingress of corrosive elements from the saline water as well as in contact with pyrites from soil with poor conductivity. The lost of passivity of concrete allows corrosion and hence, the concrete jetty's integrity is in doubt. This is why Belian have been used in the older days for marine and boat construction.

6. Density is key. The other thing that one have to consider is the density and the bulk of transportation cost. Belian have a very low density between 9KN/m3 to 13kN/m3 while concrete is almost twice the density in the range of 19kN/m3 to typical 24kN/m3. This mean by volume of transportation, it is cheaper to transport Belian wood rather than all materials involved for a concrete jetty construction. With this kind of weight for the topside, imagine the bearing capacity required on soft ground when the dead weight is twice and that does not include the imposed load. Hence, there is saving for that when it comes to foundation criteria and design.

7. Constructibility. A Belian wood jetty is easily constructed where in this case, the jetty was completed in one month while the contract period allowed is 3 months. Every contract stipulates that time is of the essence and constructibility is one of the important elements which is required and dictate the project delivery and brief. Second, it is pricy to construct concrete jetty as concrete need to be constructed in stages. Each stage, there is a need for concrete curing window that may need 5 working days or maybe 12 working days depending on the concrete mix and cement used.

For QAQC or quality control, it is a hustle to bring concrete cube specimen for compressive test to Miri. Imagine 6 cubes weighing 8kg each to Miri just to test for material conformity in six different trips (7th day and 28th day). Counter productive? Now, how about reinforcement tensile test? How about bolts? Here is the thing or issue when it comes to QAQC.

Now, raw materials for reinforced concrete required to be logistically moved and as mentioned earlier, concrete delivery is already an issue. Now, bar bending process is also an issue as it may require mobilization of machines just to bend and shape reinforcement bars based on the schedule. Imagine the surplus of resources required just to stage the form of the concrete jetty. Why not use Belian wood which comes in various sizes conform to standard size which is in accordance to all dimensions required in construction drawing. Besides this, imagine the superintending and supervision required to ensure compliance of the construction.

8. Maintenance. It is much cheaper to replace decks or bracing parts which are degraded or dilapidated compare to concrete repair and rehabilitation which is labor intensive and much more expensive to maintain.

9. There are more to write but I believe this is sufficient to give laymen the logic behind the choice of Belian Wood as main material for this particular jetty construction.

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MS 146: Hot Rolled Steel Bars for the Reinforcement of Concrete

posted May 8, 2022, 5:50 PM by jeffery jim

Many civil & structural engineers in the industry have yet to fully comprehend the need to inspect reinforcement bars before construction use. It is commonly known that most QAQC engineer will only cross check the Purchase Order to the Mill Certificate provided during offloading. But what is the essential checking before a delivery is deemed acceptable for use and compliance to the standard specification?

2. After close to 8 years since MS 146:2014 being introduced, not many fully understood the actual requirements for reinforcement periodical checking and in-situ checking. The typical requirement would be the sampling of specimens for every 30 tons of each size and each manufacturer as required by Inspection and Test Plan, JKR Standard Specification for Building Works as well as JKR Standard Specification for Road Works.

3. It is essential for site engineers attached to the contractor's QAQC team to check the reinforcement bars prior to joint inspection with consulting engineers or inspector-of-works. What are the essential checks an engineer has to conduct before signing off invoices and Material Receiving Report upon delivery?

4. There are a few things an engineer need to do before steel bundles are offloaded but first of all is primary check visually based on the Mill Certificate. First of all, for greenhorns, it is recommended that they take measurement of the steel diameter using Vernier caliper to verify the size as per Invoice. After inspecting the reinforcement size, engineers should compare the steel marking to the serial embossed on the steel reinforcement. Every steel produced shall be stamped with markings specifying the country origin and the manufacturer (or work number). Then the inspection can be continued to verify the steel grade based on the rib pattern. Many cases, purchases made were CQ (commercial quality) steel which are not recognized by MS146 due to its lack (can be substantial) in area size and mass.

5. Apart from dimension check for physical that is obvious and measurable, the Mill Certificate should be inspected for its carbon and elements content to ensure forged reinforcement bars are suitable. Another thing that one has to remember is the change that involving weldability. In superseded version(s), reinforcement bars are considered weldable but in MS 146:2014, these cannot be welded (with exception for spot weld) together with others.

6. Recently, a contractor did write in to us for this kind of approval, we rejected it unless it is proven with calculation(s). In addition to that, one has to justify how physical properties changed and workable after welding. I advised them to just tie reinforcement bars using slightly smaller reinforcement bars with proper lapping length.

7. Five specimens or samples should be made available for quality control procedures and testing. This exercise will allow engineers to conduct other physical tests. The mass per meter length and the area size should be verified and comply with the specification. For smaller reinforcement bars (below 8mm), the variation allowed is ±6% while 8mm and above will be ±4.5%. In previous revision, smaller low yield (plain hot rolled) reinforcement bars are allowed to deviate up to ±9%. The reinforcement bars are graded into G250, G460 and G500 for MS146:2006 while the latest version only recognize B500A, B500B and B500C. In most cases, structural drawings which are not updated still make reference to MS146:1997 with G460A and G460B and G250. Always double check the general notes in your drawing and highlight this to the consultant or designer. Sampled specimens should undergo tensile test in SAMM accredited laboratory to see the actual yield and tensile properties with reading on its 0.2% proof.

8. One the most common mistakes many QAQC engineer did was to only read the tensile strength of the reinforcement bar, assuming it has no limit. The stronger the reinforcement bar, the better. One has to understand that there are ceiling limits that these reinforcements have to achieve in order to performed in desired ductility. In this case, the yield strength during the tensile test should not exceed 650N/mm2. The grading is based on yield strength and therefore, all reinforcement bars should at least reach 500N/mm2. The essential ceiling limitation for G500C’s tensile over yield strength ratio should not exceed 1.35 and at least achieved 1.15. For typical G500B which are commonly used in the industry, this ratio should exceed 1.08 with total elongation at maximum force exceeding 5%.

9. After tensile test is conducted, other tests to be performed are the deformed bar bending test and deformed bar re-bend test. This to see the outcome if these reinforcement bars are still workable condition after performing these tests. We witnessed some failed tests for MS146 accredited reinforcement bars where the ductility of specimens is questionable after it cracked (torn).

I hope this write-up can guide young engineers specifically QAQC engineers to understand the importance of steel bar approval prior to use for construction purposes

May be an image of text that says "3/26/22 AM STEEL INDUSTRIES (SABAH) Sabah Steel Mile BHD 263484-U) Jalan Tuaran, Locked Bag 7,88992 Kota Kinabalu, Sabah Steel Industries (Sabah) Sdn. Bhd.: Tel: 088-427111 Fax: 088-420111 Buyer: Certificate Date. MS No.0 Description Batch Manufacturin Precess Delivery Destination MS146:2014 MS146:2014 4449:2005+A MILL CERTIFICATE fos TotalN Item certificate, ignature required. 2U22035784 0.197 0.184 0.645 0.041 0.041 0.310 0.062 0.108 0.012 0.001 0.000 30,000 0.354 111.39 tated, PHYSICALTEST R(MPa) R/R 0.874 577 Bend 678 Rebend 10.2 PASSED PASSED ESTHER JOSEPH ÛUTHRTRE"

Local Standards and Specifications

posted Apr 3, 2022, 9:19 PM by jeffery jim

A few days ago, a friend talked about a general statement which I find quite a common paradigm or paradox among local engineers. It existed in the ecosystem of engineering locally, I can certainly refer this as a dogma. It always come to my attention that local engineers always use a getaway card when confronted with their ability in determining the adaptability of foreign standards and specifications in local setting. The most irresponsible reason for a quick getaway card is to blame their alma mater for not teaching so. This renders that particular individual’s qualities – complacent, ignorant, irresponsible and to a certain degree; obstinate! This happened not only in the private sector but also within the government bodies and structures. Academia has no difference as well. All three sectors are jointly accountable for such tenet and are nexus which allows the use of such getaway card when there is an occurrence which lacks of accountability, breaches, insufficient standards of care and low duties of cares, and diminished diligence in discharging their responsibilities.

2. Construction and build environment requires finest engineers to lead the development of the country and yet, we are plagued with individuals who make no effort in upgrading themselves with common knowledge requires by the Engineer’s Act. The crux to such circumstances within the engineering community and communal ecosystem came from complacency where almost everyone within the industry tolerates and reside to such level of low value when it comes to engineering. How did such complex phenomenon be explained in parsimony?

3. There is no such thing as there is no local standard specifications without considering local settings and environment. This kind of argument is certainly coming from debilitated individuals who no longer hold the key to answer his uncertainties when confronted. There have been ongoing researches and publications of local specifications with the introduction of Malaysia Standard and standards published by smaller organizations or collective academicians and practitioners. In certain newer fields, there are morbid collection which speaks about engineering gaps, call for papers and even initial investigation which may paved a route as generally acceptable parameters and practices.

4. Let us take some examples from Malaysia Standard and some of the local settings which are considered and adopted from other foreign standards and specifications. The recent development of the Eurocode which is a transition and compilation of general specifications within the European Union (EU) from British Standard (BS), Deutsches Institut für Normung (DIN) and et cetera. These standards are then compiled and renamed with additional prefix to their code with the introduction of “EN”. Now, British Standard within the EU renamed their standard specification codes as “BS EN” while the Germans with their assigned code of “DIN EN”. In certain cases, for international acceptance and synchronization primarily with other countries such as Japan and United States, the standard specification maybe be extended and introduced with “ISO” which is part of the International Standard. The gist to such introduction allows minimal conflict in measurement. Another great example would be the American Standards for concrete by American Concrete Institute (ACI) where standards are categorized in metric and imperial units with the introduction of “M” suffix after the imperial-based code.

5. Malaysia is no different than other countries which capitalize on standards and specifications established by these developed countries. This does not mean that Malaysia allows direct adaptation without making substantial changes. If engineers spent their time making inferential between international code and local codes, they will be surprised that what local academicians and industrialists have introduced. When addenda or addendum were made for international codes, the Standard Department of Malaysia will either re-established and re-code it accordingly or introduced local annex.

6. One can conduct a retrospective study and see how some of our most common codes have developed, re-written and their continuity. For example, the development of Code of Practices for Reinforced Concrete in Malaysia setting. In the early years circa 1970, 1972 to be exact; the United Kingdom came out with CP110 which is adopted by Malaysian Engineers thereafter. This particular standard specification is bare bone standard and speak less about durability. The introduction of BS 8110 in 1985 made some adjustments and expanded into 3 volumes which highlights the needs for more robust concrete by introducing higher strength concrete based on ingression of agent and exposure which capitalizes on lower cement/water ratio for higher density and less air voids within the concrete. After two amendments and the harmonizing all European codes, BS EN 1992 series were introduced in 2004 which sees some amendment to the similar issue, which is durability of concrete. There are a few other complimentary codes which need to be read in the light of BS EN 1992 which is BS EN 1990, BS EN 1991 and BS EN 1998. Partial Safety Factor is the main change and it is not limited to reduction from ratio of 1.6 to 1.5 for imposed load but also further reduction when condition(s) is far feasible and permissible. In local setting, Malaysia came out with MS 1195:1991 where some tweaking to suit local conditions were made based on the BS8110:1985 and now superseded and replaced by MS EN 1992. MS EN 1992 is not a direct copy of BS EN 1992 but it is akin to the mentioned British counterpart and referred as Local Annex. Adjustments and presumptions were made to suit the country’s condition. Therefore, it is an invalid and more over obstinate to state that an engineer is not aware about the suitability of existing codes for local context.

7. Another code that sees effort of the country structural specialists and academicians is the Code of Practice on Wind Loading for Building which sees the introduction of MS1553:2002 where wind speed envelopes were introduced specifically based on local studies and exposures. The migration from MS1553:2002 to MS EN 1991-1-4 finally occurred in 2017 with more comprehensive researches have been done for a fixed parameter for further wind speed calculation. Similarly, the changes and adaptation of seismic peak ground acceleration computation with the newly introduced MS EN 1998 based on a simple study of rock background which will due to be updated in years to come as suggested by the panels.

8. Based on these paragraphs, I would say that there is no way a design engineer or engineers generally within the country to not know the whole development and the use of appropriate codes. Worst, to lament blatantly on the lack of standards and specifications built for our local setting in not only irresponsible but a mirror which renders the kind of engineers we encounter these days.

9. Now, who are to be blamed when we are facing engineers who have been carrying a creed to heart where they can vindicate their ignorance without shame? All three! The government bodies who are empowered did not forcefully enforced the need for proper justifications and used of local setting although in recent years, I see design briefs are checked by Independent Checking Engineers (ICE). The Private design and construction firm is to be blamed for not equipping their design office with local standards, specifications and related annexes. For these group of professionals which I have encountered most time when doing design check, the wrong interpretation and design brief may lead to colossal variation in price. A change from 0.05 G to 0.08G in earthquake design may lead to increase of steel capacity by 15% and may lead to additional RM2 million for medium size development. Lastly, academicians should step up and understand the local scenarios and issues and stop relying in making references based on text books and slides provided by publishers from the West.

10. I hope this particular write-up will be an eye-opener to many of you and put to end a non-existence issue of not knowing the local standards and specifications when these standards and specifications are three to four times cheaper (almost subsidized) compare to our other international counterparts. If I were to say that engineers are accountable based on Tort Law, would you still try to vindicate yourself with ignorance in front the honourable judge and spend time in jail because you do not read enough? Think and reflect; go and read a book.

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