Syahrul Senin | Uitm Pp (original) (raw)

Papers by Syahrul Senin

Proceedings of the Second International Conference on the Future of ASEAN (ICoFA) 2017 – Volume 2, 2018

Soft clay settlement is well known as a major problem in the civil engineering structures such as... more Soft clay settlement is well known as a major problem in the civil engineering structures such as highways, buildings and bridges. The problem arises due to the current settlement analysis which is derived from the effective stress concept. It considers the volume change increase with the increase in the effective stress, whereas the settlement problem is not always happened in this fashion. In fact, the inundation problem that causes the sudden settlement during the effective stress decrease really put a tremendous blow to this concept. It is proved that the empirical effective stress concept that is widely used by the engineer is not the appropriate analysis. In fact, this is one of the main factors that cause many settlement problems. The objective of this paper is to review several settlement models available in the literature and to distinguish the applicability of the model to predict soil settlement. It also reviewed the volume change behaviour by incorporating shear strength concept that is more appropriate to predict the settlement. Hopefully, this paper will help the new researcher to uncover the unique behaviour of clay settlement and at the same time will reduce the settlement problem cases.

Proceedings of the Second International Conference on the Future of ASEAN (ICoFA) 2017 – Volume 2, 2018

Generally, a construction structure is located on a by soil preferably a good and sound soil prop... more Generally, a construction structure is located on a by soil preferably a good and sound soil properties. However due to limited location of a good and sound soil properties, engineers were challenge by constructing a structure on a problematic soil condition. Mostly, the engineer will be facing building a structure on a loose sandy soil and worst it has a higher chance of liquefaction. This sandy soil can cause the problem to the structure of the building especially if the bearing capacity of the soil is not adequate. For example, the settlement, cracking will happen due to the earthquakes phenomena and worst-case scenario the building will have to undergo a liquefaction attack aftershock. Thus, to overcome this serious problem, the soil properties must be improved by a suitable method such as soil stabilization. The objective of this research is to assess the effectiveness of using fly ash and bottom ash on soil stabilization in liquefaction condition. In this research, piling was used to increase the density of the soil. This will help to reduce the number of settlement during liquefaction process. The amount of cement (5% of soil weight) and fly ash with bottom ash is used with different percentages (10, 20, 30, 40%). The sand will be mixed with the bottom ash and fly ash in different percentages. After conducting a series of tests, it is concluded that 30% of bottom and fly ash give a better result in reducing the settlement value than other mixture.

Jurnal Teknologi, 2013

In this study, the reduction of ground penetrating radar (GPR) signal amplitude magnitudes were m... more In this study, the reduction of ground penetrating radar (GPR) signal amplitude magnitudes were measured to monitor the reinforcing steel corrosion in concrete slab. Geophysical Survey System Incorporation (GSSI) BridgeScan system which includes a SIR-3000 Windows, based on portable GPR data collection with 1.6 GHz ground-couple antenna has been used to generate electromagnetic waves and analysis of the signal on a slab sample. Four 16 mm diameter reinforcing steel were embedded in a 255 mm x 455 mm x 60 mm grade 40 concrete slab in the transverse direction and three in the longitudinal. The slab was immersed in concentrated sodium chloride solution (8 g/l) for three months to simulate the corrosive environment on the reinforced slab. The average signal amplitude decreases from 1139.75 dB (at day 7) to-404.25 dB (at day 61) and finally drop to-782.75 dB (at day 93) as the corrosion process progressing. The presence of corrosion activity on the reinforcing steel was confirmed based on the potential difference reading by Half Cell (HC) which shows that the reinforcing steel experienced probability of corrosion level by more than 90 % after 61 and 93 days. GPR method is found to be a promising approach as it possesses high sensitivity towards changes in amplitude at par with high potential changes in HC method in corrosion detection.

Jurnal Teknologi, 2015

This paper focused on the effect of various moisture and chloride content on the direct and refle... more This paper focused on the effect of various moisture and chloride content on the direct and reflected waves (DW and RW) of Ground Penetrating Radar (GPR) amplitude ratio of concrete slab. The GPR is used in detecting both corrosion agents of 13 numbers of concrete (water/cement ratio= 0.7) slab samples. Radar measurement is employed on a fixed point of the samples to measure two signals referred to as the direct and reflected radar waves amplitudes. Simple signal processing on the collected time domain signal plots is executed by MATLAB® software to compute the attenuation of peak-to-peak amplitude of DW and RW which are normalized with respect to the peak-to-peak amplitude of DW recorded in air. From the analysis, strong linear relationships (R2 = 0.82 and 0.96) for water content variation of DW and RW are found. However, a very weak linear relationship with R2 of 0.31 for chloride content variation of DW but a strong linear relationship (R2 = 0.95) for the RW are established. Thes...

Jurnal Teknologi, 2015

The presence of inevitable air void defects in reinforced concrete components due to poor qualit... more The presence of inevitable air void defects in reinforced concrete components due to poor quality control during construction can further aggravate the moisture and chloride penetration in concrete to accelerate the corrosion process of the reinforcing steel. Non-destructive test (NDT) methods, Ground Penetrating Radar (GPR) and Impact-Echo (IE), are utilised tp detect the void defects. This study is to compare the accuracy and limitations of both methods in detecting the sizes and depths of the air voids. The sample is a 600 × 400 ×200 mm3 reinforced grade 40 concrete slab with embedded air voids in the sample. The air-voids are introduced in the concrete slab by positioning air-void plastic balls with diameters of 67, 45, 27, 20 and 3 mm each at the depths of 70, 80, 100, 80 and 80 mm, respectively, from the top surface of the slab. Results show that GPR can detect the air voids with sizes larger than 20 mm in diameter with error ranging from -8.9 to 30% from their actual diamet...

This study is focused on the analysis of the composite materials by using the developed computer ... more This study is focused on the analysis of the composite materials by using the developed computer program, Automatic Composite Laminated Analysis Program (ACLAP), in FORTRAN language. The purposes of this study are to determine the capability and the accuracy of the program for solving the analysis that related with the laminate materials. This study also can provide an understanding of the underlying principles and techniques associated with the stress analysis and strength predictions of composite material structures.There are six examples that are going to be analyzing by using the FORTRAN program, each of the examples has their own problem statement. The FORTRAN results from the examples will be compared with the theory calculation. At the end of this study a user friendly computer program is produced with the intention to assist the lecturer for teaching or learning purpose.

Construction and Building Materials, 2016

Abstract The detection of moisture and chloride ingress through concrete cover is important for e... more Abstract The detection of moisture and chloride ingress through concrete cover is important for estimating the extent of corrosion in reinforced concrete (RC) components. The concentrations of the substances are monitored by observing the ground penetrating radar (GPR) amplitude attenuation in water and chloride saturated concrete slab samples. The amplitude attenuation significantly correlates with the amount of both substances. Two multiple nonlinear regression models were developed. The proposed models demonstrate a strong correlation with the radar amplitude attenuation data as both substances are varied in the concrete cover. The developed models can be employed to estimate the moisture and free chloride content in – concrete cover for improved quantification of corrosion level.

The failure of bolted connections will present serious economic and human consequences, so it is ... more The failure of bolted connections will present serious economic and human consequences, so it is important to obtain a better understanding of the structural behavior of bolted connections. The objective of this study is to find the best numerical bolt model and analyzing their behavior when subjected to tensile loads. There are three models of bolt will be analyze for this study. First model was analysed using brick element, second model using beam element and the third model bolt using joint element. For this study the finite element software, LUSAS will be used to study various connection models. Convergence study was conducted in this research. For this study, it was found that the brick element is the best model as compared with the beam element and joint element.

Numerical analysis is concerned with the accurate and efficient evaluation of mathematical expres... more Numerical analysis is concerned with the accurate and efficient evaluation of mathematical expressions, especially on computers with floating point arithmetic. While scientists have always been concerned to some extent with numerical computation, the modern discipline of numerical analysis is almost entirely a product of the period since 1950, during which there has been an explosion in the availability of electronic computers. There are three main issues: 1. to organize computations so that there is minimum accumulation of error in floating point arithmetic 2. to organize computations efficiently, so that they consume the least possible resources 3. to obtain accurate numerical approximations to quantities which may not have explicit mathematical expressions. In other words, do it accurately, do it quickly, and do it cheaply. It might be thought that numerical evaluation consists largely of

Civil Engineering and Architecture

Structural Health Monitoring (SHM) is a crucial scope of work in civil engineering specifically o... more Structural Health Monitoring (SHM) is a crucial scope of work in civil engineering specifically on monitoring the in-service and ageing coastal bridge deck concrete structure serviceability and limit state status performance. One of the possible natural process that pose detrimental effects to such structure performance monitoring is the steel rebar pitting corrosion problem. Progressive pitting corrosion process on the certain steel rebar area in low quality of concrete cover due to chloride ingression will cause local premature damage the steel rebar which obviously affect the serviceability performance of the structural element, i.e. displacement. However, the available displacement monitoring methods become an issue when it comes to engineering practicality and costs considerations. Therefore, the purpose of this study is to monitor and analyze the vertical displacement of an undamaged and damage reinforced concrete beam using the digital signal processing technology, Digital Im...

IOP Conference Series: Earth and Environmental Science

Train has been one of the essential and convenient transportation choices for community nowadays.... more Train has been one of the essential and convenient transportation choices for community nowadays. Instead of carrying a passenger, these types of facilities also can be used to transport material across our country. With the increasing usage of train every year, the rate of accidents has also increased dramatically. Therefore, the importance of studying about the railway can contribute to building better and comfort railway track which can deliver their services at its best for an extended period. This study focused on the measurement of the deflection of concrete sleepers which affect the performance of the railway track. Lack of actual deflection value from the site can be problematic to ensure the quality of the track itself. The method used for the analysis is by using the Sirius-M instrument which can be recorded and analyses the acceleration of the concrete sleepers when receiving the loading wave from a moving train. The data of acceleration then can be transformed into defle...

Journal of Physics: Conference Series

Corrosion of rebars in reinforced concrete structure is a big universal problem created by saline... more Corrosion of rebars in reinforced concrete structure is a big universal problem created by saline water ingress causing rebar and other metal structural member to corrode. The deterioration of concrete structures due to the harsh environment conditions leads to the deterioration of the reinforced concrete performance structure, and the premature deterioration of the structure before completing due to carbonation or the chloride content of the future services is expected to be the primary concern for engineers and researchers. Progress of corrosion location cannot be visually evaluated until the point when crack or a delamination is appearing. Therefore, in the study, the Ground Penetrating Radar (GPR) is used to investigate the artificial rebar corrosion damage on steel rebars. The methods showed the artificial rebar corrosion damage can be detected and quantified without damaging the surrounding concrete material. GPR showed the potential on detecting rebar corrosion damage on larg...

Many mathematical models developed to predict the stress-strain curve of soil. Most of them are c... more Many mathematical models developed to predict the stress-strain curve of soil. Most of them are complicated because of the complexity nature of soil material. Moreover, soil behavior is apparently unpredictable due to the fact that every type of soil has its own inherent properties that cannot be represented by a single model. Hence, the objectives of this paper is to review the mathematical models available in the literature and to assess the applicability, limitation and the basic requirement in order to apply the models. Also, this paper will look on the basic principles of the models and the basic characteristic that should have on the models for the best prediction capability. This paper will review the basic models such as th elastic models (Hooke's law and hyperbolic models), simple elastic plastic models (Drucker-Prager, Mohr Coulomb, DiMaggio-Sandler, PLAXIS Soft Soil and Lade and Duncan), Critical State Soil Models (Modified Cam Clay, elasto-viscoplastic, Structured Cam Clay, Anisotropic Cam Clay) and Bounding surface models (Dafalias and MIT-E3). Some weaknesses will also be highlighted to shed some light for further improvements. BASIC CHARACTERISTICS OF A MATHEMATICAL MODEL Here are the essential characteristics that should have for a mathematical model [1]. The model must capable to capture the important features of the stress-strain curve under different loading conditions The model must be based on reliable theoretical frameworks The required parameter must be obtained easily from standard tests so that the applicability of the model will not be hindered by the non-standard experiment that hard to replicate

Concrete delamination is a problem commonly found in reinforced concrete bridge deck and may caus... more Concrete delamination is a problem commonly found in reinforced concrete bridge deck and may cause severe damage to the structural component. The need to access the severity of this defect is pertinent as the detachment of the concrete cover from the rebar is invisible and only showing when cracks and spalling had reached the top of asphalt layer. Most of the bridge inspections on concrete delamination rely on human interpretation based on visual inspection (VI). VI is a very subjective assessment and should be conducted by highly trained bridge inspectors. It is also a time consuming method. Alternatively, Ground Penetrating Radar (GPR) is a rapid and nondestructive method to detect rebar delaminations within the bridge deck and quantify this defect based on the reflection of electromagnetic waves by the air void within the delamination. Therefore, VI and GPR method were employed at a case study site to detect the location of the delamination and to estimate the extent of its sever...

The upgrading of the Northern-Southern Railway Line to accommodate for future High Speed Rail (HS... more The upgrading of the Northern-Southern Railway Line to accommodate for future High Speed Rail (HSR) soon to be constructed. The nature of soil between places are varied thus create a problems for railway engineers to lay down Prestressed Concrete Sleeper (PCS). Soil-structure interaction is very important to ensure any structure stand and distribute the load to ground. A lot of cases has been reported due to low soil-structure interaction. The sign of a low soil structure interaction can be seen in short or longer period of time. PCS were located directly above ground and if the soilstructure interaction is low, the result will be catastrophic. There have been reported that certain rail track line were located at a problematic soil (settlement) and the rail engineer have to monitor the situation on regular basis. Hence, this research aims to understand more about the relationship between the PCS and soil thus creating awareness to relevant authorities to tackle this problem.

Generally, a construction structure is located on a by soil preferably a good and sound soil prop... more Generally, a construction structure is located on a by soil preferably a good and sound soil properties. However due to limited location of a good and sound soil properties, engineers were challenge by constructing a structure on a problematic soil condition. Mostly, the engineer will be facing building a structure on a loose sandy soil and worst it has a higher chance of liquefaction. This sandy soil can cause the problem to the structure of the building especially if the bearing capacity of the soil is not adequate. For example, the settlement, cracking will happen due to the earthquakes phenomena and worst-case scenario the building will have to undergo a liquefaction attack aftershock. Thus, to overcome this serious problem, the soil properties must be improved by a suitable method such as soil stabilization. The objective of this research is to assess the effectiveness of using fly ash and bottom ash on soil stabilization in liquefaction condition. In this research, piling was ...

Proceedings of the Second International Conference on the Future of ASEAN (ICoFA) 2017 – Volume 2, 2018

Soft clay settlement is well known as a major problem in the civil engineering structures such as... more Soft clay settlement is well known as a major problem in the civil engineering structures such as highways, buildings and bridges. The problem arises due to the current settlement analysis which is derived from the effective stress concept. It considers the volume change increase with the increase in the effective stress, whereas the settlement problem is not always happened in this fashion. In fact, the inundation problem that causes the sudden settlement during the effective stress decrease really put a tremendous blow to this concept. It is proved that the empirical effective stress concept that is widely used by the engineer is not the appropriate analysis. In fact, this is one of the main factors that cause many settlement problems. The objective of this paper is to review several settlement models available in the literature and to distinguish the applicability of the model to predict soil settlement. It also reviewed the volume change behaviour by incorporating shear strength concept that is more appropriate to predict the settlement. Hopefully, this paper will help the new researcher to uncover the unique behaviour of clay settlement and at the same time will reduce the settlement problem cases.

Proceedings of the Second International Conference on the Future of ASEAN (ICoFA) 2017 – Volume 2, 2018

Generally, a construction structure is located on a by soil preferably a good and sound soil prop... more Generally, a construction structure is located on a by soil preferably a good and sound soil properties. However due to limited location of a good and sound soil properties, engineers were challenge by constructing a structure on a problematic soil condition. Mostly, the engineer will be facing building a structure on a loose sandy soil and worst it has a higher chance of liquefaction. This sandy soil can cause the problem to the structure of the building especially if the bearing capacity of the soil is not adequate. For example, the settlement, cracking will happen due to the earthquakes phenomena and worst-case scenario the building will have to undergo a liquefaction attack aftershock. Thus, to overcome this serious problem, the soil properties must be improved by a suitable method such as soil stabilization. The objective of this research is to assess the effectiveness of using fly ash and bottom ash on soil stabilization in liquefaction condition. In this research, piling was used to increase the density of the soil. This will help to reduce the number of settlement during liquefaction process. The amount of cement (5% of soil weight) and fly ash with bottom ash is used with different percentages (10, 20, 30, 40%). The sand will be mixed with the bottom ash and fly ash in different percentages. After conducting a series of tests, it is concluded that 30% of bottom and fly ash give a better result in reducing the settlement value than other mixture.

Jurnal Teknologi, 2013

In this study, the reduction of ground penetrating radar (GPR) signal amplitude magnitudes were m... more In this study, the reduction of ground penetrating radar (GPR) signal amplitude magnitudes were measured to monitor the reinforcing steel corrosion in concrete slab. Geophysical Survey System Incorporation (GSSI) BridgeScan system which includes a SIR-3000 Windows, based on portable GPR data collection with 1.6 GHz ground-couple antenna has been used to generate electromagnetic waves and analysis of the signal on a slab sample. Four 16 mm diameter reinforcing steel were embedded in a 255 mm x 455 mm x 60 mm grade 40 concrete slab in the transverse direction and three in the longitudinal. The slab was immersed in concentrated sodium chloride solution (8 g/l) for three months to simulate the corrosive environment on the reinforced slab. The average signal amplitude decreases from 1139.75 dB (at day 7) to-404.25 dB (at day 61) and finally drop to-782.75 dB (at day 93) as the corrosion process progressing. The presence of corrosion activity on the reinforcing steel was confirmed based on the potential difference reading by Half Cell (HC) which shows that the reinforcing steel experienced probability of corrosion level by more than 90 % after 61 and 93 days. GPR method is found to be a promising approach as it possesses high sensitivity towards changes in amplitude at par with high potential changes in HC method in corrosion detection.

Jurnal Teknologi, 2015

This paper focused on the effect of various moisture and chloride content on the direct and refle... more This paper focused on the effect of various moisture and chloride content on the direct and reflected waves (DW and RW) of Ground Penetrating Radar (GPR) amplitude ratio of concrete slab. The GPR is used in detecting both corrosion agents of 13 numbers of concrete (water/cement ratio= 0.7) slab samples. Radar measurement is employed on a fixed point of the samples to measure two signals referred to as the direct and reflected radar waves amplitudes. Simple signal processing on the collected time domain signal plots is executed by MATLAB® software to compute the attenuation of peak-to-peak amplitude of DW and RW which are normalized with respect to the peak-to-peak amplitude of DW recorded in air. From the analysis, strong linear relationships (R2 = 0.82 and 0.96) for water content variation of DW and RW are found. However, a very weak linear relationship with R2 of 0.31 for chloride content variation of DW but a strong linear relationship (R2 = 0.95) for the RW are established. Thes...

Jurnal Teknologi, 2015

The presence of inevitable air void defects in reinforced concrete components due to poor qualit... more The presence of inevitable air void defects in reinforced concrete components due to poor quality control during construction can further aggravate the moisture and chloride penetration in concrete to accelerate the corrosion process of the reinforcing steel. Non-destructive test (NDT) methods, Ground Penetrating Radar (GPR) and Impact-Echo (IE), are utilised tp detect the void defects. This study is to compare the accuracy and limitations of both methods in detecting the sizes and depths of the air voids. The sample is a 600 × 400 ×200 mm3 reinforced grade 40 concrete slab with embedded air voids in the sample. The air-voids are introduced in the concrete slab by positioning air-void plastic balls with diameters of 67, 45, 27, 20 and 3 mm each at the depths of 70, 80, 100, 80 and 80 mm, respectively, from the top surface of the slab. Results show that GPR can detect the air voids with sizes larger than 20 mm in diameter with error ranging from -8.9 to 30% from their actual diamet...

This study is focused on the analysis of the composite materials by using the developed computer ... more This study is focused on the analysis of the composite materials by using the developed computer program, Automatic Composite Laminated Analysis Program (ACLAP), in FORTRAN language. The purposes of this study are to determine the capability and the accuracy of the program for solving the analysis that related with the laminate materials. This study also can provide an understanding of the underlying principles and techniques associated with the stress analysis and strength predictions of composite material structures.There are six examples that are going to be analyzing by using the FORTRAN program, each of the examples has their own problem statement. The FORTRAN results from the examples will be compared with the theory calculation. At the end of this study a user friendly computer program is produced with the intention to assist the lecturer for teaching or learning purpose.

Construction and Building Materials, 2016

Abstract The detection of moisture and chloride ingress through concrete cover is important for e... more Abstract The detection of moisture and chloride ingress through concrete cover is important for estimating the extent of corrosion in reinforced concrete (RC) components. The concentrations of the substances are monitored by observing the ground penetrating radar (GPR) amplitude attenuation in water and chloride saturated concrete slab samples. The amplitude attenuation significantly correlates with the amount of both substances. Two multiple nonlinear regression models were developed. The proposed models demonstrate a strong correlation with the radar amplitude attenuation data as both substances are varied in the concrete cover. The developed models can be employed to estimate the moisture and free chloride content in – concrete cover for improved quantification of corrosion level.

The failure of bolted connections will present serious economic and human consequences, so it is ... more The failure of bolted connections will present serious economic and human consequences, so it is important to obtain a better understanding of the structural behavior of bolted connections. The objective of this study is to find the best numerical bolt model and analyzing their behavior when subjected to tensile loads. There are three models of bolt will be analyze for this study. First model was analysed using brick element, second model using beam element and the third model bolt using joint element. For this study the finite element software, LUSAS will be used to study various connection models. Convergence study was conducted in this research. For this study, it was found that the brick element is the best model as compared with the beam element and joint element.

Numerical analysis is concerned with the accurate and efficient evaluation of mathematical expres... more Numerical analysis is concerned with the accurate and efficient evaluation of mathematical expressions, especially on computers with floating point arithmetic. While scientists have always been concerned to some extent with numerical computation, the modern discipline of numerical analysis is almost entirely a product of the period since 1950, during which there has been an explosion in the availability of electronic computers. There are three main issues: 1. to organize computations so that there is minimum accumulation of error in floating point arithmetic 2. to organize computations efficiently, so that they consume the least possible resources 3. to obtain accurate numerical approximations to quantities which may not have explicit mathematical expressions. In other words, do it accurately, do it quickly, and do it cheaply. It might be thought that numerical evaluation consists largely of

Civil Engineering and Architecture

Structural Health Monitoring (SHM) is a crucial scope of work in civil engineering specifically o... more Structural Health Monitoring (SHM) is a crucial scope of work in civil engineering specifically on monitoring the in-service and ageing coastal bridge deck concrete structure serviceability and limit state status performance. One of the possible natural process that pose detrimental effects to such structure performance monitoring is the steel rebar pitting corrosion problem. Progressive pitting corrosion process on the certain steel rebar area in low quality of concrete cover due to chloride ingression will cause local premature damage the steel rebar which obviously affect the serviceability performance of the structural element, i.e. displacement. However, the available displacement monitoring methods become an issue when it comes to engineering practicality and costs considerations. Therefore, the purpose of this study is to monitor and analyze the vertical displacement of an undamaged and damage reinforced concrete beam using the digital signal processing technology, Digital Im...

IOP Conference Series: Earth and Environmental Science

Train has been one of the essential and convenient transportation choices for community nowadays.... more Train has been one of the essential and convenient transportation choices for community nowadays. Instead of carrying a passenger, these types of facilities also can be used to transport material across our country. With the increasing usage of train every year, the rate of accidents has also increased dramatically. Therefore, the importance of studying about the railway can contribute to building better and comfort railway track which can deliver their services at its best for an extended period. This study focused on the measurement of the deflection of concrete sleepers which affect the performance of the railway track. Lack of actual deflection value from the site can be problematic to ensure the quality of the track itself. The method used for the analysis is by using the Sirius-M instrument which can be recorded and analyses the acceleration of the concrete sleepers when receiving the loading wave from a moving train. The data of acceleration then can be transformed into defle...

Journal of Physics: Conference Series

Corrosion of rebars in reinforced concrete structure is a big universal problem created by saline... more Corrosion of rebars in reinforced concrete structure is a big universal problem created by saline water ingress causing rebar and other metal structural member to corrode. The deterioration of concrete structures due to the harsh environment conditions leads to the deterioration of the reinforced concrete performance structure, and the premature deterioration of the structure before completing due to carbonation or the chloride content of the future services is expected to be the primary concern for engineers and researchers. Progress of corrosion location cannot be visually evaluated until the point when crack or a delamination is appearing. Therefore, in the study, the Ground Penetrating Radar (GPR) is used to investigate the artificial rebar corrosion damage on steel rebars. The methods showed the artificial rebar corrosion damage can be detected and quantified without damaging the surrounding concrete material. GPR showed the potential on detecting rebar corrosion damage on larg...

Many mathematical models developed to predict the stress-strain curve of soil. Most of them are c... more Many mathematical models developed to predict the stress-strain curve of soil. Most of them are complicated because of the complexity nature of soil material. Moreover, soil behavior is apparently unpredictable due to the fact that every type of soil has its own inherent properties that cannot be represented by a single model. Hence, the objectives of this paper is to review the mathematical models available in the literature and to assess the applicability, limitation and the basic requirement in order to apply the models. Also, this paper will look on the basic principles of the models and the basic characteristic that should have on the models for the best prediction capability. This paper will review the basic models such as th elastic models (Hooke's law and hyperbolic models), simple elastic plastic models (Drucker-Prager, Mohr Coulomb, DiMaggio-Sandler, PLAXIS Soft Soil and Lade and Duncan), Critical State Soil Models (Modified Cam Clay, elasto-viscoplastic, Structured Cam Clay, Anisotropic Cam Clay) and Bounding surface models (Dafalias and MIT-E3). Some weaknesses will also be highlighted to shed some light for further improvements. BASIC CHARACTERISTICS OF A MATHEMATICAL MODEL Here are the essential characteristics that should have for a mathematical model [1]. The model must capable to capture the important features of the stress-strain curve under different loading conditions The model must be based on reliable theoretical frameworks The required parameter must be obtained easily from standard tests so that the applicability of the model will not be hindered by the non-standard experiment that hard to replicate

Concrete delamination is a problem commonly found in reinforced concrete bridge deck and may caus... more Concrete delamination is a problem commonly found in reinforced concrete bridge deck and may cause severe damage to the structural component. The need to access the severity of this defect is pertinent as the detachment of the concrete cover from the rebar is invisible and only showing when cracks and spalling had reached the top of asphalt layer. Most of the bridge inspections on concrete delamination rely on human interpretation based on visual inspection (VI). VI is a very subjective assessment and should be conducted by highly trained bridge inspectors. It is also a time consuming method. Alternatively, Ground Penetrating Radar (GPR) is a rapid and nondestructive method to detect rebar delaminations within the bridge deck and quantify this defect based on the reflection of electromagnetic waves by the air void within the delamination. Therefore, VI and GPR method were employed at a case study site to detect the location of the delamination and to estimate the extent of its sever...

The upgrading of the Northern-Southern Railway Line to accommodate for future High Speed Rail (HS... more The upgrading of the Northern-Southern Railway Line to accommodate for future High Speed Rail (HSR) soon to be constructed. The nature of soil between places are varied thus create a problems for railway engineers to lay down Prestressed Concrete Sleeper (PCS). Soil-structure interaction is very important to ensure any structure stand and distribute the load to ground. A lot of cases has been reported due to low soil-structure interaction. The sign of a low soil structure interaction can be seen in short or longer period of time. PCS were located directly above ground and if the soilstructure interaction is low, the result will be catastrophic. There have been reported that certain rail track line were located at a problematic soil (settlement) and the rail engineer have to monitor the situation on regular basis. Hence, this research aims to understand more about the relationship between the PCS and soil thus creating awareness to relevant authorities to tackle this problem.

Generally, a construction structure is located on a by soil preferably a good and sound soil prop... more Generally, a construction structure is located on a by soil preferably a good and sound soil properties. However due to limited location of a good and sound soil properties, engineers were challenge by constructing a structure on a problematic soil condition. Mostly, the engineer will be facing building a structure on a loose sandy soil and worst it has a higher chance of liquefaction. This sandy soil can cause the problem to the structure of the building especially if the bearing capacity of the soil is not adequate. For example, the settlement, cracking will happen due to the earthquakes phenomena and worst-case scenario the building will have to undergo a liquefaction attack aftershock. Thus, to overcome this serious problem, the soil properties must be improved by a suitable method such as soil stabilization. The objective of this research is to assess the effectiveness of using fly ash and bottom ash on soil stabilization in liquefaction condition. In this research, piling was ...