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This paper presents an experimental study to analyse the bonding strength between geopolymer concrete (GC) and normal concrete (NC) bond substrate. Three different strengths of GC which were 80 MPa, 85 MPa and 90 MPa were bonded to 30 MPa NC and denoted as NC30-GC80, NC30-GC85 and NC30-GC90. Slant shear and split tensile tests were conducted to investigate the bonding strength between two different substrates. The effect of bonding was then determined by using Mohr-Coulomb theory where critical bonding condition (smooth surface) was created. From the analysis, it was found that NC30-GC80 had the most powerful self-adhesion between GC towards NC. This result indicated the highest bonding strength of GC to NC at critical condition. Such strong bond was obtained by the effect of self-adhesive from GC to NC. The self-adhesive characteristic which represented by pure shear strength was obtained from Mohr-Coulomb theory.

This paper presents an experimental study to analyse the bonding strength between geopolymer concrete (GC) and normal concrete (NC) bond substrate. Three different strengths of GC which were 80 MPa, 85 MPa and 90 MPa were bonded to 30 MPa NC and denoted as NC30-GC80, NC30-GC85 and NC30-GC90. Slant shear and split tensile tests were conducted to investigate the bonding strength between two different substrates. The effect of bonding was then determined by using Mohr-Coulomb theory where critical bonding condition (smooth surface) was created. From the analysis, it was found that NC30-GC80 had the most powerful self-adhesion between GC towards NC. This result indicated the highest bonding strength of GC to NC at critical condition. Such strong bond was obtained by the effect of self-adhesive from GC to NC. The self-adhesive characteristic which represented by pure shear strength was obtained from Mohr-Coulomb theory.

This paper presents an experimental study to analyse the bonding strength between geopolymer concrete (GC) and normal concrete (NC) bond substrate. Three different strengths of GC which were 80 MPa, 85 MPa and 90 MPa were bonded to 30 MPa NC and denoted as NC30-GC80, NC30-GC85 and NC30-GC90. Slant shear and split tensile tests were conducted to investigate the bonding strength between two different substrates. The effect of bonding was then determined by using Mohr-Coulomb theory where critical bonding condition (smooth surface) was created. From the analysis, it was found that NC30-GC80 had the most powerful self-adhesion between GC towards NC. This result indicated the highest bonding strength of GC to NC at critical condition. Such strong bond was obtained by the effect of self-adhesive from GC to NC. The self-adhesive characteristic which represented by pure shear strength was obtained from Mohr-Coulomb theory.

The strength of concrete structures deteriorates after exposure to fire. Strength loss varies with elevated temperature, fire duration, and the mechanical properties of concrete. Repairing and strengthening affected structures are important to improve their performances. Fire-damaged concrete has been repaired using fiber-reinforcing polymer. The superior properties of ultrahigh performance fiber-reinforced concrete (UHPFRC) make it suitable as a repair material. Furthermore, an excellent repair material should be able to bond properly with the substrate and maintain its structural integrity. The aim of this paper is to review the potential use of UHPFRRC as a repair material for fire-damaged concrete in terms of bond strength. Previous studies showed that developing efficient rehabilitation techniques that enable fire-damaged structures to be restored has some challenges.  Whether UHPFRC can be used as a repair material particularly for fire-damaged concrete structure is recommended to be proven in future studies.

The strength of concrete structures deteriorates after exposure to fire. Strength loss varies with elevated temperature, fire duration, and the mechanical properties of concrete. Repairing and strengthening affected structures are important to improve their performances. Fire-damaged concrete has been repaired using fiber-reinforcing polymer. The superior properties of ultrahigh performance fiber-reinforced concrete (UHPFRC) make it suitable as a repair material. Furthermore, an excellent repair material should be able to bond properly with the substrate and maintain its structural integrity. The aim of this paper is to review the potential use of UHPFRRC as a repair material for fire-damaged concrete in terms of bond strength. Previous studies showed that developing efficient rehabilitation techniques that enable fire-damaged structures to be restored has some challenges.  Whether UHPFRC can be used as a repair material particularly for fire-damaged concrete structure is recommended to be proven in future studies.

The construction sector is a key component of a nation’s gross domestic product, but its inherent nature results in potentially dangerous conditions that affect the safety of all workers on construction projects (CPs). Therefore, the original idea of the research is to determine the relationship between safety system (SS) during the implementation phase (IPh) of CPs and the minimisation of waste (materials, time and cost). Achieving a lean construction work requires suitable planning, safety considerations and waste resource minimisation throughout the project cycle. This research aims to identify and rank the safety factors during the IPh of a CP, which will have positive effects on minimising waste. Information and data were gathered from the existing literature and the structured interviews and questionnaire survey conducted among 111 randomly selected construction companies. Questionnaire results were evaluated using statistical tools, such as hypothesis testing, analysis of variance and linear regression. This research identified and ranked 24 important safety factors with positive effects on minimising waste in CPs during IPh. The seven most important safety factors that should be considered to minimise material, time and cost wastage are as follows: handling, management, external factors, workers, procurement, site condition and appropriate scaffolding for SS. The best linear model was developed on the basis of the importance index of the identified factors. This model can predict the minimisation of waste (materials, time and cost) in CPs by using SS. Thus, the safety criteria and SS should be used during IPh to minimise waste on the basis of the developed model.

The construction sector is a key component of a nation’s gross domestic product, but its inherent nature results in potentially dangerous conditions that affect the safety of all workers on construction projects (CPs). Therefore, the original idea of the research is to determine the relationship between safety system (SS) during the implementation phase (IPh) of CPs and the minimisation of waste (materials, time and cost). Achieving a lean construction work requires suitable planning, safety considerations and waste resource minimisation throughout the project cycle. This research aims to identify and rank the safety factors during the IPh of a CP, which will have positive effects on minimising waste. Information and data were gathered from the existing literature and the structured interviews and questionnaire survey conducted among 111 randomly selected construction companies. Questionnaire results were evaluated using statistical tools, such as hypothesis testing, analysis of variance and linear regression. This research identified and ranked 24 important safety factors with positive effects on minimising waste in CPs during IPh. The seven most important safety factors that should be considered to minimise material, time and cost wastage are as follows: handling, management, external factors, workers, procurement, site condition and appropriate scaffolding for SS. The best linear model was developed on the basis of the importance index of the identified factors. This model can predict the minimisation of waste (materials, time and cost) in CPs by using SS. Thus, the safety criteria and SS should be used during IPh to minimise waste on the basis of the developed model.

The construction sector is a key component of a nation’s gross domestic product, but its inherent nature results in potentially dangerous conditions that affect the safety of all workers on construction projects (CPs). Therefore, the original idea of the research is to determine the relationship between safety system (SS) during the implementation phase (IPh) of CPs and the minimisation of waste (materials, time and cost). Achieving a lean construction work requires suitable planning, safety considerations and waste resource minimisation throughout the project cycle. This research aims to identify and rank the safety factors during the IPh of a CP, which will have positive effects on minimising waste. Information and data were gathered from the existing literature and the structured interviews and questionnaire survey conducted among 111 randomly selected construction companies. Questionnaire results were evaluated using statistical tools, such as hypothesis testing, analysis of variance and linear regression. This research identified and ranked 24 important safety factors with positive effects on minimising waste in CPs during IPh. The seven most important safety factors that should be considered to minimise material, time and cost wastage are as follows: handling, management, external factors, workers, procurement, site condition and appropriate scaffolding for SS. The best linear model was developed on the basis of the importance index of the identified factors. This model can predict the minimisation of waste (materials, time and cost) in CPs by using SS. Thus, the safety criteria and SS should be used during IPh to minimise waste on the basis of the developed model.

This research aimed at studying the effect of sulfate attack on the compressive concrete strength with various percentages of recycled aggregate replacements (0%, 30%, 60% and 100%). Water cement ratio (0.42) are used, MgSO4 solution was used with two concentration (6% and 9 %) to represent the effect of sulfate attack on the concrete compressive strength. The experimental tests focused on physical properties of recycled aggregate; density, unit weight, sieve analysis, Los Angles test and specific gravity. Tests have also been performed on 108 concrete cubes samples at 7 days, 14 days and 28 days for compressive strength. The results of  compressive strength at 28 days using (0%, 30%, 60% and 100%) recycled aggregate are (330, 280, 266 and 244) Kg/cm2 respectively, with reduction in compressive strength was (15.2%, 19.4% and 26%)  for replacement ratio (30%, 60% and 100%) respectively. MgSO4 solution has an effect on compressive strength after 90 days of immersion in 6% and 9% concentrated of MgSO4 solution. The results of this study show that the reduction in compressive strength using recycled aggregate is more sensitive against the sulfate attack compared with natural aggregate.

This research aimed at studying the effect of sulfate attack on the compressive concrete strength with various percentages of recycled aggregate replacements (0%, 30%, 60% and 100%). Water cement ratio (0.42) are used, MgSO4 solution was used with two concentration (6% and 9 %) to represent the effect of sulfate attack on the concrete compressive strength. The experimental tests focused on physical properties of recycled aggregate; density, unit weight, sieve analysis, Los Angles test and specific gravity. Tests have also been performed on 108 concrete cubes samples at 7 days, 14 days and 28 days for compressive strength. The results of  compressive strength at 28 days using (0%, 30%, 60% and 100%) recycled aggregate are (330, 280, 266 and 244) Kg/cm2 respectively, with reduction in compressive strength was (15.2%, 19.4% and 26%)  for replacement ratio (30%, 60% and 100%) respectively. MgSO4 solution has an effect on compressive strength after 90 days of immersion in 6% and 9% concentrated of MgSO4 solution. The results of this study show that the reduction in compressive strength using recycled aggregate is more sensitive against the sulfate attack compared with natural aggregate.

This research aimed at studying the effect of sulfate attack on the compressive concrete strength with various percentages of recycled aggregate replacements (0%, 30%, 60% and 100%). Water cement ratio (0.42) are used, MgSO4 solution was used with two concentration (6% and 9 %) to represent the effect of sulfate attack on the concrete compressive strength. The experimental tests focused on physical properties of recycled aggregate; density, unit weight, sieve analysis, Los Angles test and specific gravity. Tests have also been performed on 108 concrete cubes samples at 7 days, 14 days and 28 days for compressive strength. The results of  compressive strength at 28 days using (0%, 30%, 60% and 100%) recycled aggregate are (330, 280, 266 and 244) Kg/cm2 respectively, with reduction in compressive strength was (15.2%, 19.4% and 26%)  for replacement ratio (30%, 60% and 100%) respectively. MgSO4 solution has an effect on compressive strength after 90 days of immersion in 6% and 9% concentrated of MgSO4 solution. The results of this study show that the reduction in compressive strength using recycled aggregate is more sensitive against the sulfate attack compared with natural aggregate.

This research aimed at studying the effect of sulfate attack on the compressive concrete strength with various percentages of recycled aggregate replacements (0%, 30%, 60% and 100%). Water cement ratio (0.42) are used, MgSO4 solution was used with two concentration (6% and 9 %) to represent the effect of sulfate attack on the concrete compressive strength. The experimental tests focused on physical properties of recycled aggregate; density, unit weight, sieve analysis, Los Angles test and specific gravity. Tests have also been performed on 108 concrete cubes samples at 7 days, 14 days and 28 days for compressive strength. The results of  compressive strength at 28 days using (0%, 30%, 60% and 100%) recycled aggregate are (330, 280, 266 and 244) Kg/cm2 respectively, with reduction in compressive strength was (15.2%, 19.4% and 26%)  for replacement ratio (30%, 60% and 100%) respectively. MgSO4 solution has an effect on compressive strength after 90 days of immersion in 6% and 9% concentrated of MgSO4 solution. The results of this study show that the reduction in compressive strength using recycled aggregate is more sensitive against the sulfate attack compared with natural aggregate.