ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve ... more ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve the insulating characteristics of construction materials with the purpose of economical construction, lightweight aggregate (LWA) concrete (LWAC) could be pondered. In this paper, the effect of different parameters such as volume fraction, LWA grading and sand to cement ratio on compressive strength, and elastic modulus of lightweight concrete have been studied. In this study, 36 different mix designs were developed; 3 different sand to cement ratios, 4 volume fractions and 3 different gradings of LWA were considered in order to study the effect of these parameters and find out an efficient mix design for structural use. In order to investigate the effect of each parameter on the compressive strength and elastic modulus, a multivariate analysis of variation was performed. Results indicate that the volume fraction and the LWA grading are the two key parameters influencing compressive strength comparing with sand to cement ratios. Moreover, it was concluded that the sand to cement (S/C) ratio could be as effective as other parameters on elastic modulus of LWAC.
The use of composite materials such as Fiber Reinforced Polymer (FRP) to strengthen concrete stru... more The use of composite materials such as Fiber Reinforced Polymer (FRP) to strengthen concrete structures has surged during the past two decades as an alternative for conventional methods of structural strengthening and repair. FRP materials are light and relatively easy to install. They are noncorrosive, durable and less vulnerable to environmental conditions in comparison to other construction and retrofitting materials. The knowledge and applications of composites for strengthening steel structures are relatively smaller when compared to concrete strengthening applications. Strengthening-By-Stiffening (SBS) is a new strengthening alternative that was developed at Louisiana State University. SBS has proven to be a practical technique for inhibiting local buckling in shear-controlled steel beams. This technique relies on the out-of-plane stiffness of pultruded composite sections as opposed to the in-plane strength of thin composites that is often reported in the literature. Prelimina...
ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve ... more ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve the insulating characteristics of construction materials with the purpose of economical construction, lightweight aggregate (LWA) concrete (LWAC) could be pondered. In this paper, the effect of different parameters such as volume fraction, LWA grading and sand to cement ratio on compressive strength, and elastic modulus of lightweight concrete have been studied. In this study, 36 different mix designs were developed; 3 different sand to cement ratios, 4 volume fractions and 3 different gradings of LWA were considered in order to study the effect of these parameters and find out an efficient mix design for structural use. In order to investigate the effect of each parameter on the compressive strength and elastic modulus, a multivariate analysis of variation was performed. Results indicate that the volume fraction and the LWA grading are the two key parameters influencing compressive strength comparing with sand to cement ratios. Moreover, it was concluded that the sand to cement (S/C) ratio could be as effective as other parameters on elastic modulus of LWAC.
Building sector in most countries around the world requires large amounts of heating and cooling ... more Building sector in most countries around the world requires large amounts of heating and cooling energy. Indeed, building cooling loads due to solar gains are responsible for approximately half of global cooling load. In addition, windows are considered as one of the important sources of energy loss in buildings. In order to minimize this loss, shading devices can be installed in the exterior part of the window to reduce solar heat. The objective of this study is to investigate the simultaneous effect of glazing, shading materials, and configuration of shading devices on total building energy consumption in different climate regions in the United States. To achieve this objective, a typical residential building was selected to assess the effect of the aforementioned parameters on total energy consumption in five main climate regions. A series of simulations were conducted using EnergyPlus simulation program to quantify energy consumption in each scenario and determine the most energ...
International Journal of Adhesion and Adhesives, 2015
ABSTRACT Strengthening-By-Stiffening (SBS) is a novel technique whose purpose is to improve struc... more ABSTRACT Strengthening-By-Stiffening (SBS) is a novel technique whose purpose is to improve structural strength by stiffening buckling-prone regions in thin-walled steel structures using pultruded composite sections. A proof of concept study showed that SBS can achieve gains in shear strength of up to 56% using glass fiber reinforced polymers (GFRP) sections. This paper presents experimental results showing the effect of adhesive type on the efficiency of SBS for shear-deficient thin-walled steel beams. Specimens strengthened with two adhesive types were tested; a generic type (Type I) that is typically used for FRP-strengthening of concrete structures and a relatively new type (Type II) that is particularly promoted for steel structures. Like most FRP-strengthened structures, a debonding failure mode was observed for SBS specimens strengthened using adhesive Type I. Conversely, specimens strengthened using adhesive Type II did not fail by debonding, but rather by buckling of the smaller (less slender) shear panels. The resulting ductile failure mode is uncommon for FRP strengthening techniques and can lead to new applications of FRP strengthening for steel structures that were not possible using more brittle adhesives with lower capacity to absorb inelastic energy.
Building sector in most countries around the world requires large amounts of heating and cooling ... more Building sector in most countries around the world requires large amounts of heating and cooling energy. Indeed, building cooling loads due to solar gains are responsible for approximately half of global cooling load. In addition, windows are considered as one of the important sources of energy loss in buildings. In order to minimize this loss, shading devices can be installed in the exterior part of the window to reduce solar heat. The objective of this study is to investigate the simultaneous effect of glazing, shading materials, and configuration of shading devices on total building energy consumption in different climate regions in the United States. To achieve this objective, a typical residential building was selected to assess the effect of the aforementioned parameters on total energy consumption in five main climate regions. A series of simulations were conducted using EnergyPlus simulation program to quantify energy consumption in each scenario and determine the most energ...
ABSTRACT The use of nano-sized titanium dioxide (TiO2) as coating in buildings has received consi... more ABSTRACT The use of nano-sized titanium dioxide (TiO2) as coating in buildings has received considerable interests in recent years due to its excellent ability to purify the environment by capturing some of the pollutants in the air and by using its inherent photocatalytic properties to its advantage. This study employs Life Cycle Assessment (LCA) to evaluate the use of nano-sized titanium dioxide coating on residential window glass. To achieve this objective, this study compiled a Life-Cycle Inventory (LCI) for quantifying the energy and emissions of the coating during the manufacturing process and in-service. The Building for Environmental and Economic Sustainability (BEES) model was employed to develop the life cycle inventory of titanium dioxide coating on windows. The LCA framework used in this study was based on a life cycle methodology that follows the International Organization for Standardization (ISO) 14040 standard for life cycle assessment and the ASTM standard for Multi-attribute Decision Analysis. Based on the analysis conducted, it may be concluded that the use of TiO2 coating on window panes carries a positive effect on acidification potential, eutrophication potential, criteria air pollutants and smog formation potential, while it increases environmental loads in global warming, fossil fuel depletion, water intake, human health, and ecological toxicity. However, the overall normalized performance on the environment and air purification is positive.
ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve ... more ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve the insulating characteristics of construction materials with the purpose of economical construction, lightweight aggregate (LWA) concrete (LWAC) could be pondered. In this paper, the effect of different parameters such as volume fraction, LWA grading and sand to cement ratio on compressive strength, and elastic modulus of lightweight concrete have been studied. In this study, 36 different mix designs were developed; 3 different sand to cement ratios, 4 volume fractions and 3 different gradings of LWA were considered in order to study the effect of these parameters and find out an efficient mix design for structural use. In order to investigate the effect of each parameter on the compressive strength and elastic modulus, a multivariate analysis of variation was performed. Results indicate that the volume fraction and the LWA grading are the two key parameters influencing compressive strength comparing with sand to cement ratios. Moreover, it was concluded that the sand to cement (S/C) ratio could be as effective as other parameters on elastic modulus of LWAC.
The use of composite materials such as Fiber Reinforced Polymer (FRP) to strengthen concrete stru... more The use of composite materials such as Fiber Reinforced Polymer (FRP) to strengthen concrete structures has surged during the past two decades as an alternative for conventional methods of structural strengthening and repair. FRP materials are light and relatively easy to install. They are noncorrosive, durable and less vulnerable to environmental conditions in comparison to other construction and retrofitting materials. The knowledge and applications of composites for strengthening steel structures are relatively smaller when compared to concrete strengthening applications. Strengthening-By-Stiffening (SBS) is a new strengthening alternative that was developed at Louisiana State University. SBS has proven to be a practical technique for inhibiting local buckling in shear-controlled steel beams. This technique relies on the out-of-plane stiffness of pultruded composite sections as opposed to the in-plane strength of thin composites that is often reported in the literature. Prelimina...
ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve ... more ABSTRACT In order to reduce the dead load of the structures prone to seismic hazards and improve the insulating characteristics of construction materials with the purpose of economical construction, lightweight aggregate (LWA) concrete (LWAC) could be pondered. In this paper, the effect of different parameters such as volume fraction, LWA grading and sand to cement ratio on compressive strength, and elastic modulus of lightweight concrete have been studied. In this study, 36 different mix designs were developed; 3 different sand to cement ratios, 4 volume fractions and 3 different gradings of LWA were considered in order to study the effect of these parameters and find out an efficient mix design for structural use. In order to investigate the effect of each parameter on the compressive strength and elastic modulus, a multivariate analysis of variation was performed. Results indicate that the volume fraction and the LWA grading are the two key parameters influencing compressive strength comparing with sand to cement ratios. Moreover, it was concluded that the sand to cement (S/C) ratio could be as effective as other parameters on elastic modulus of LWAC.
Building sector in most countries around the world requires large amounts of heating and cooling ... more Building sector in most countries around the world requires large amounts of heating and cooling energy. Indeed, building cooling loads due to solar gains are responsible for approximately half of global cooling load. In addition, windows are considered as one of the important sources of energy loss in buildings. In order to minimize this loss, shading devices can be installed in the exterior part of the window to reduce solar heat. The objective of this study is to investigate the simultaneous effect of glazing, shading materials, and configuration of shading devices on total building energy consumption in different climate regions in the United States. To achieve this objective, a typical residential building was selected to assess the effect of the aforementioned parameters on total energy consumption in five main climate regions. A series of simulations were conducted using EnergyPlus simulation program to quantify energy consumption in each scenario and determine the most energ...
International Journal of Adhesion and Adhesives, 2015
ABSTRACT Strengthening-By-Stiffening (SBS) is a novel technique whose purpose is to improve struc... more ABSTRACT Strengthening-By-Stiffening (SBS) is a novel technique whose purpose is to improve structural strength by stiffening buckling-prone regions in thin-walled steel structures using pultruded composite sections. A proof of concept study showed that SBS can achieve gains in shear strength of up to 56% using glass fiber reinforced polymers (GFRP) sections. This paper presents experimental results showing the effect of adhesive type on the efficiency of SBS for shear-deficient thin-walled steel beams. Specimens strengthened with two adhesive types were tested; a generic type (Type I) that is typically used for FRP-strengthening of concrete structures and a relatively new type (Type II) that is particularly promoted for steel structures. Like most FRP-strengthened structures, a debonding failure mode was observed for SBS specimens strengthened using adhesive Type I. Conversely, specimens strengthened using adhesive Type II did not fail by debonding, but rather by buckling of the smaller (less slender) shear panels. The resulting ductile failure mode is uncommon for FRP strengthening techniques and can lead to new applications of FRP strengthening for steel structures that were not possible using more brittle adhesives with lower capacity to absorb inelastic energy.
Building sector in most countries around the world requires large amounts of heating and cooling ... more Building sector in most countries around the world requires large amounts of heating and cooling energy. Indeed, building cooling loads due to solar gains are responsible for approximately half of global cooling load. In addition, windows are considered as one of the important sources of energy loss in buildings. In order to minimize this loss, shading devices can be installed in the exterior part of the window to reduce solar heat. The objective of this study is to investigate the simultaneous effect of glazing, shading materials, and configuration of shading devices on total building energy consumption in different climate regions in the United States. To achieve this objective, a typical residential building was selected to assess the effect of the aforementioned parameters on total energy consumption in five main climate regions. A series of simulations were conducted using EnergyPlus simulation program to quantify energy consumption in each scenario and determine the most energ...
ABSTRACT The use of nano-sized titanium dioxide (TiO2) as coating in buildings has received consi... more ABSTRACT The use of nano-sized titanium dioxide (TiO2) as coating in buildings has received considerable interests in recent years due to its excellent ability to purify the environment by capturing some of the pollutants in the air and by using its inherent photocatalytic properties to its advantage. This study employs Life Cycle Assessment (LCA) to evaluate the use of nano-sized titanium dioxide coating on residential window glass. To achieve this objective, this study compiled a Life-Cycle Inventory (LCI) for quantifying the energy and emissions of the coating during the manufacturing process and in-service. The Building for Environmental and Economic Sustainability (BEES) model was employed to develop the life cycle inventory of titanium dioxide coating on windows. The LCA framework used in this study was based on a life cycle methodology that follows the International Organization for Standardization (ISO) 14040 standard for life cycle assessment and the ASTM standard for Multi-attribute Decision Analysis. Based on the analysis conducted, it may be concluded that the use of TiO2 coating on window panes carries a positive effect on acidification potential, eutrophication potential, criteria air pollutants and smog formation potential, while it increases environmental loads in global warming, fossil fuel depletion, water intake, human health, and ecological toxicity. However, the overall normalized performance on the environment and air purification is positive.
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Papers by Hamed Babaizadeh