Structural Health Monitoring Based Time- Dependent Reliabilityanalysis of Concrete Bridge

The presence of chloride ions in concrete is the most important cause of steel reinforcing corrosion. Corrosion can lead to structural damage and needs to be managed effectively for better allocation of resources and effective bridge management. The application of de-icing salt or atmospheric exposure in marine environment could be the cause of corrosion initiation. This paper reviews chloride ingress prediction model and presents methodology to improve confidence in predicting corrosion concentration taking into account time dependent reliability analysis. Modeling uncertainty is often associated with limited knowledge which it can be reduced by increasing the availability of data. Additional information through bridge inspection and monitoring will increase confidence in prediction models. Monte Carlo simulation with Latin Hypercube Sampling is used to estimate prior and posterior performance prediction for chloride concentration. Bayesian Updating is used to incorporate prior beliefs about the condition and performance of the bridge together with data obtained through inspections and health monitoring to produce more quantitative data. The application of Bayesian Updating is shown to considerably reduce uncertainties associated with performance prediction. By using this approach, it will lead to the prediction of structural performance with increased confidence

Effect of Mixing Ingredient on Compressive Strength of Oil Palm Shell Lightweight Aggregate Concrete Containing Palm Oil Fuel Ash

AbstractThe increasingly generated oil palm shell (OPS) and palm oil fuel ash (POFA) which is a by-product of Malaysian palm oil mills annually, has lead towards the effort of integrating palm oil fuel ash as mineral admixture in lightweight aggregate concrete which produced using 100% oil palm shell as lightweight aggregate. This paper addresses the compressive strength of this oil palm shell lightweight aggregate concrete upon usage of different ash replacement level, water cement ratio, superplasticiser, sand and cement content. At the early state of investigation, cubes of (100x100x100mm) containing various replacement level of ash were produced and tested for it compressive strength. Then, the 20% replacement levels of POFA which give the highest compressive strength value were used for further experimental work. Experimental work to investigate the effect of water content, percentage of superplasticiser, sand content and amount of cement used were conducted using two types of mixes. Plain oil palm shell lightweight aggregate concrete (0% POFA) as reference specimen, and oil palm shell lightweight aggregate containing 20% palm oil fuel ash (20% POFA) were prepared in form of cubes. All the specimens were subjected to water curing until the testing date. The compressive strength test was conducted following the procedures in BSEN 12390 – 3 at 28 days. Integration of 20% POFA in oil palm shell lightweight aggregate concrete leads to production of a greener lightweight aggregate concrete product with optimum strength. Inclusion too much of water should be avoided as it diminishes the concrete compressive strength. Only right formulation of palm oil fuel ash, water, superplasticizer, sand and cement content would be able to produce oil palm shell lightweight aggregate concrete containing palm oil fuel ash exhibiting optimum strength

Mechanical properties of synthetic lightweight coarse aggregate infuse with offshore sand

Alternative replacement for land aggregate is very important for island and coastal region where land aggregate resources is scarce, expensive and even unavailable for construction industries. For country that have limited sources of land aggregate, offshore sand is a potential choice of replacement for their construction industries. This research studied the production and usage of synthetic lightweight coarse aggregate produced using offshore sand (SYLCAG). SYLCAG was produced to replace coarse aggregate that normally use igneous rock for concrete production. It was produced with density of 1300 kg/m3 which is nearly 60% lighter than normal aggregate. This SYLCAG was used as a full replacement for coarse aggregate in concrete which then produced as a concrete with density almost 1900 kg/m3. The produced concrete did not have achieve the design strength of 25 MPa concrete using the standard concrete design. However, it still has the potential to be develop with higher design and later used as structural concrete

Application of Flexural Timber Reinforcement in Light Concrete Beam Structure

Timber is a capable alternative for reinforcement in concrete beam because it possesses high strength ratio compare to its weight although its strength is incompatible to steel. This study was conducted to highlight the flexural behaviour of beam reinforced with two types of timber; Balau and Meranti. Comparisons of behaviour have been made between samples applying the Reinforced Concrete Design to EC2. The result of flexural test shows that steel reinforcement beam (SRB) carried the utmost loads compared to timber sample beam which reinforced with Balau (BRB) and Meranti (MRB). Compared to the flexural strength of SRB, BRB reached about 69 % of the value while MRB reached to 66 % respectively. It was found that the failure mode of the timber beam was closely related to the load-deflection behaviour same as conventional steel beam. The larger the load-deflection value, the wider the range of cracking occurred

Synthetic Lightweight Coarse Aggregate using Offshore Sand

Offshore sand is a capable alternative replacement for land aggregate in concrete. It is necessity for some country or regional where land aggregate is scarce and sometimes unavailable to be used for development but offshore sand is accessible for replacement. This paper reports about the production and usage of synthetic lightweight coarse aggregate produced using offshore sand (SYLCAG). It was produced with density of 1300 kg/m3 which is nearly 60% lighter than normal aggregate. This SYLCAG was used as a full replacement for coarse aggregate in concrete which then produced as a concrete with density almost 1900 kg/m3. The produced concrete did not have a good strength with design of 25 MPa concrete. However, it still has the potential to be develop with higher design and later used as structural concret

Performance of Grouted Splice Sleeve Connector Under Tensile Load

Grouted splice sleeve connector system takes the advantages of bond-slip resistance of grout and mechanical gripping of reinforcement bars to provide resistance to the tensile force. In this system,grout acts as a load transferring medium and bonding material between bars and sleeve. This study adopted the end-to-end rebars connection method to investigate the effect of development length and sleeve diameter to the bonding performance of sleeve connector. The end-to-end method is referring to the condition where reinforcement bars were inserted into the sleeve from both ends and meet at the center before grout is filled. Eight specimens of grouted splice sleeve connector were tested under tensile load to determine their performance. Sleeve connector was designed using 5 mm thick circular hollow section (CHS) steel pipe and consisted of one external and two internal sleeves. The tensile test results show that connector with smaller external and internal sleeve diameter appear to provide better bonding performance. Three types of failure were observed in this research, which are bar fracture (outside the sleeve), bar pullout, and internal sleeve pullout. With reference to these failure types, development length of 200 mm is the optimum value due to its bar fracture type, which indicates the tensile capacity of the connector is higher than the reinforcement bar

Structural Performance of Grouted Sleeve Connectors with and without Transverse Reinforcement for Precast Concrete Structure

This paper presents the performance of the proposed grouted sleeve connector with and without steel spiral as transverse reinforcement under incremental tensile load until failure. The connector utilized mild steel pipe as sleeve where the sleeve consists of external and internal sleeve with the diameter of the external sleeve is larger than internal sleeve. The mild steel pipe and the steel spiral are used to confine and reinforce the grout and the two discontinued bars spliced end-to-end configuration in the sleeve. The test shows that, there are two modes of failure which were bar slipped and bar fractured outside the sleeve. Eleven specimens out of fourteen shows satisfactory results as it failed due to bar fractured outside the sleeve and achieve satisfactory ultimate tensile capacity. The stiffness and the ductility of the connectors also satisfy. Grouted sleeve connectors with steel spiral perform better compared to connectors without a steel spiral. The test shows that the performance of the grouted sleeve connector with or without steel spiral was governed by grout-bar bond, anchorage length and confinement action provided by the sleeve and the steel spiral. The connectors have a potential to be used in connecting precast concrete structure

Effect of Mixing Ingredient on Compressive Strength of Oil Palm Shell Lightweight Aggregate Concrete Containing Palm Oil Fuel Ash

The increasingly generated oil palm shell (OPS) and palm oil fuel ash (POFA) which is a by-product of Malaysian palm oil mills annually, has lead towards the effort of integrating palm oil fuel ash as mineral admixture in lightweight aggregate concrete which produced using 100% oil palm shell as lightweight aggregate. This paper addresses the compressive strength of this oil palm shell lightweight aggregate concrete upon usage of different ash replacement level, water cement ratio, superplasticiser, sand and cement content. At the early state of investigation, cubes of (100x100x100 mm) containing various replacement level of ash were produced and tested for it compressive strength. Then, the 20% replacement levels of POFA which give the highest compressive strength value were used for further experimental work. Experimental work to investigate the effect of water content, percentage of superplasticiser, sand content and amount of cement used were conducted using two types of mixes. Plain oil palm shell lightweight aggregate concrete (0% POFA) as reference specimen, and oil palm shell lightweight aggregate containing 20% palm oil fuel ash (20% POFA) were prepared in form of cubes. All the specimens were subjected to water curing until the testing date. The compressive strength test was conducted following the procedures in BSEN 12390 – 3 at 28 days. Integration of 20% POFA in oil palm shell lightweight aggregate concrete leads to production of a greener lightweight aggregate concrete product with optimum strength. Inclusion too much of water should be avoided as it diminishes the concrete compressive strength. Only right formulation of palm oil fuel ash, water, superplasticizer, sand and cement content would be able to produce oil palm shell lightweight aggregate concrete containing palm oil fuel ash exhibiting optimum strength

Teams That Teach and Learn using Steered Module in Civil Engineering Courses (TELUS MOD): An Overview

Learning style of Malaysian civil engineering students appear to be too dependent on lecture contact hours. They do not realize that in actual almost 70% of the notional learning hours should be students own individual learning hours. Still, very few students learn individually but yet it is hard to ascertain this claim. Therefore, this paper presents an overview on team learning method where steered modules are introduced with aims to help students in appreciating their individual learning hours. This method brings in the team that learns and teaches each other without supervision from instructors. This paper found that team-learning method would benefit students in varying ways

Assessment on Traffic Noise Pollution in Malaysia

The transportation system and its technology in Malaysia continues to evolve over time to meet the challenges towards fulfilling the aspirations of the people. The rapid development in the transportation system is of concern due to its significant effects on the environment and human health. Almost all human activities including traffic and transportation contribute to pollution such as noise and it has become an inevitable issue