This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Cementitious materials being the most prospective building blocks achieving their absolute streng... more Cementitious materials being the most prospective building blocks achieving their absolute strength to avoid the deterioration in the early stage of service life is ever-demanding. Minimizing the labor and capital-intensive maintenance and repair cost is a critical challenge. Thus, self-healing mortars with modified strength are proposed. Lately, selfhealing of micro-cracks by introducing bacteria during the formation of mortar or concrete became attractive. Self-healing with polymeric admixtures is considered to be relatively more durable and faster process. Certainly, the self-healing of synthetic polymeric materials is inspired by biological systems, where the damage triggers an autonomic healing response. This emerging and fascinating research initiative may significantly improve the durability and the safety limit of the polymeric components potential for assorted applications. In this work, using epoxy resin (diglycidyl ether of bisphenol A) without any hardener as admixture polymeric-cementitious materials is prepared. These epoxy-modified mortars are synthesized with various polymer-cement ratios subjected to initial wet/dry curing (WDC) together with long term dry curing (DC). Their self-healing function and hardening effects are evaluated via preloading and drying of the specimens, chemical analysis, and ultrasonic pulse velocity testing. It is demonstrated that 10% of polymer is the best proportion for polymer-cement ratio. Furthermore, the wet/dry curing is established to be superior process for healing hairline cracks present in the mortar. The excellent features of the results suggest that our novel method may constitute a basis for improving the compressive strength and self-healing features of mortars.
h i g h l i g h t s Compressive capacity enhancement in cold-formed steel composite column. Compo... more h i g h l i g h t s Compressive capacity enhancement in cold-formed steel composite column. Composite assembled with ferro-cement jacket and bolts. Three types of bolts with four diameter sizes. Higher column ultimate load capacity with higher wire mesh layers and bolts diameter.
Abstract of Emerging Trends in Scientific Research, 2015
In conventional composite construction for buildings and bridges, Hot-Rolled Steel (HRS) section ... more In conventional composite construction for buildings and bridges, Hot-Rolled Steel (HRS) section is well known to be used. The composite action is usually achieved by using conventional headed stud shear connectors. However, for Cold-Formed Steel (CFS) section, the use of headed stud shear connectors is not feasible as the section is very thin and incapable to be weld. Therefore, a suitable shear connection system of bolt and nut is proposed in this study by varying the size of the bolted shear connectors. This paper presents the prospect of using a bolt and nut as shear connector that could be well-suited with CFS section when integrated in Self-Compacting Concrete (SCC). The experimental test comprised of push-out and was conducted to determine the strength and ductility of the proposed bolted shear connectors as used in composite construction. Eight push-out test specimens of bolted shear connector size consist of M12, M14 and M16 of grade 8.8 were fabricated and tested to failure. The experimental results show that the bolted shear connectors used to possess good shear resistance capacity. Influence of varying the size of the bolted shear connectors was investigated. The results show that the size of bolted shear connectors influenced the ultimate strength capacity of the shear connectors significantly.
This paper describes the results of an ongoing test program to evaluate the performance of polyme... more This paper describes the results of an ongoing test program to evaluate the performance of polymer-modified cement-based mortars for repairing surfaces up to a depth of 75 mm (3 inches) of concrete structures damaged due to exposure to cold climates. Twenty-five selected commercially available polymer-modified products, seven containing styrene butadiene rubber (SBR) and 18 containing acrylics were evaluated. They were compared with a pure cement-based mortar containing 8 percent silica fume with a water/(cement + silica fume) (W/C) ratio of 0.31. All mortars were subjected to physical and mechanical tests. This paper also presents the performance of the three best polymer-modified cement-based mortars (included in the 25 mortars), installed in 1992 on two spillways of a dam in a very severe environment. The six inspections so far have found that these three products are still performing well after an exposure to very low temperatures for a period of four years.
Abstract: Applications such as soil, rock, and oil-well grouting all require enormous amounts of ... more Abstract: Applications such as soil, rock, and oil-well grouting all require enormous amounts of cement and are therefore good examples of areas where high volumes of ground slag or pozzolans such as fly ash could partially replace cement to produce low-cost, ...
The study evaluated the impact of graphene powders used as additives in the recipe of the experim... more The study evaluated the impact of graphene powders used as additives in the recipe of the experimental lime mortar to a mixture ratio of 1:2.5 of NHL3.5 hydraulic lime:fine sand. The content of binder, aggregate and water was kept constant, varying only the amount and the type of the added additives in relation to the amount of natural hydraulic lime NHL3.5. The following five types of experimental mortars were prepared as follows: reference mortar (without additive); mortars containing 1 wt.% GO and 5 wt.% GO powder; mortar with the following GO powders mixture: GO powder functionalized with silver nanoparticles and with fly ash (GO-Ag + GO-fly ash); mortar with the following GO powders mixture: GO with zinc oxide and with titanium oxide (GO-ZnO + GO-TiO2). The influence of the GO-based additive addition on the porosity, surface microstructure, and water sorption coefficient of the mortar samples was evaluated. The antibacterial effect of the mortar samples against three bacterial ...
Schwefel. ‐ Die Struktur und vor allem die i magnetischen Eigenschaften von Mischkristallen der Z... more Schwefel. ‐ Die Struktur und vor allem die i magnetischen Eigenschaften von Mischkristallen der Zusammensetzung (I) werden untersucht.
Proceedings of the Institution of Civil Engineers, Apr 1, 2019
Waste coconut shell (CS) was used to produce nano charcoal ash (NCA) as a potential modifier mate... more Waste coconut shell (CS) was used to produce nano charcoal ash (NCA) as a potential modifier material in an asphalt binder. This study focused on the microstructural and physical properties of NCA. Thermogravimetric analysis and derivative thermogravimetric analysis (TGA/DTA), field emission scanning electron microscopy (FESEM), X-ray fluorescence, particle size analysis (PSA), penetration tests, softening point tests and dynamic shear rheometer (DSR) tests were performed. The TGA/DTA results revealed 490°C to be a suitable CS burning temperature to form carbon and to reduce impurities. The morphology determined by FESEM showed that charcoal CS presents a smooth, porous and irregular shape. The carbon content on the surface of the material was 77•6%, as indicated by energy-dispersive X-ray spectroscopy. PSA showed that the optimum size of the charcoal CS obtained after several grinding cycles was 148 nm. Test results indicated that adding NCA from coconut shell to bitumen improved the binder stiffness up to 47% and significantly increased the softening point up to 12% compared with virgin binder. The DSR test revealed that the optimum size of NCA enhanced the bitumen by increasing the resistance to rutting until a temperature of 76°C was reached, prior to failure at a temperature of 82°C.
"SP-126: Durability of Concrete: Second International Conference, Montreal, Canada 1991"
Erosion by abrasion, cavitation and/or chemical attack in concrete hydraulic structures deteriora... more Erosion by abrasion, cavitation and/or chemical attack in concrete hydraulic structures deteriorates spillways, stilling basins, chutes, slabs and transverse joints, concrete blocks under water gates and any irregular surface subjected to high water flow rate. Countless overlays are commercially available for repairing deteriorated surfaces. However, the essential data provided by manufacturers is very limited and, even if it is available, it is normally limited to room temperature values. This persuaded Canadian Electrical Association to financially support a comprehensive study on commercial overlays, especially from the viewpoint of resistance against erosion and the severe climatic conditions observed in northern parts of Canada. This paper presents laboratory test data on the erosion resistance and durability properties of various types of commercial overlays such as comentitious grouts, polymer-modified cement-based mortars and epoxy mortars.
The intake concrete tunnel at Bersimis-1 generating station is coated with a black sticky substan... more The intake concrete tunnel at Bersimis-1 generating station is coated with a black sticky substance (slime) approximately 5 mm in thickness. Since the tunnel is 12 km long and has an average internal diameter of 9.45 m, the deposit represents a considerable obstacle to the production of electric power. The resulting loss of power generated is estimated to be around 39 MW per year, valued at 71 million dollars. Inspections in 1979, 1981, and 1983 showed that simply cleaning the surfaces would reduce the power losses but the slime built up again after a few years. A thin, smooth protective coating, containing anti-slime agents, compatible with the existing concrete could protect the surfaces against erosion and limit the slime deposit and its harmful effect on power production. The 1993 inspection provided an opportunity both to analyze the concrete, the slime itself, and the water and to experiment with the various methods of cleaning the surface and applying the different coating products. In 1994, 11 other products were selected for the specified characteristics and applied on concrete pipes and installed at two different locations: one consisted of submerged concrete specimens in the Bersimis river and in the second test setup, the products were installed by creating an artificial environment similar to the tunnel conditions using the tunnel water. The results showed that some products do not resist these conditions. Abrasion resistance tests in the laboratory confirmed these observations. One of the eleven products, a polymer-modified cement-based mortar, passed the submersion test and was applied to a small surface area (125 m 2) of the tunnel during a generating station shutdown in 1995. The thickness of the mortar required to cover the walls of the tunnel was between 2 and 3 mm. The total cost of repairing with the mortar was estimated to be between 10 and 11 million dollars. The size of the tunnel, its restricted accessibility, cleaning, ecological disposal of the slime, and the large quantities of material to be applied to cover the entire tunnel added to the complexity of the project.
One of the essential steps for planning solid waste management towards sustainable development is... more One of the essential steps for planning solid waste management towards sustainable development is to reuse solid waste in the construction industry. Coal is one of the world's most important sources of energy, fueling almost 40 % of electricity worldwide. Malaysia is commonly producing electricity through burning millions of tonnes of coal. This process generates around 8.5 Mt of coal ash, which comprised of 80 % Fly Ash (FA), and 20 % Bottom Ash (BA) as waste. The study aims to investigate the workability, compressive strength and leachability of concrete containing BA and FA as replacement of sand and cement. Cement was substituted with 20 % of FA by mass and fine aggregate was replaced with BA at 0, 20, 50, 75 and 100 % in the concrete mix. The results show that the percentage sum of SiO2, Al2O3 and Fe2O3 (the main chemical composition in coal ash) in FA and BA are about 78.82 % and 83.24 %. The leaching test showed that the heavy metal concentrations in leachates are much lo...
h i g h l i g h t s Flow characteristics of ternary blended self-consolidating mortar. Self-conso... more h i g h l i g h t s Flow characteristics of ternary blended self-consolidating mortar. Self-consolidating mortar incorporating palm oil fuel ash (POFA) and pulverised burnt clay (PBC). Effect of high range water reducer (HRWR) on the blend of POFA and PBC. Flow ability of the various mortars with different mix proportion. Addition of a blended POFA and PBC prevented the bleeding of the mortars.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Cementitious materials being the most prospective building blocks achieving their absolute streng... more Cementitious materials being the most prospective building blocks achieving their absolute strength to avoid the deterioration in the early stage of service life is ever-demanding. Minimizing the labor and capital-intensive maintenance and repair cost is a critical challenge. Thus, self-healing mortars with modified strength are proposed. Lately, selfhealing of micro-cracks by introducing bacteria during the formation of mortar or concrete became attractive. Self-healing with polymeric admixtures is considered to be relatively more durable and faster process. Certainly, the self-healing of synthetic polymeric materials is inspired by biological systems, where the damage triggers an autonomic healing response. This emerging and fascinating research initiative may significantly improve the durability and the safety limit of the polymeric components potential for assorted applications. In this work, using epoxy resin (diglycidyl ether of bisphenol A) without any hardener as admixture polymeric-cementitious materials is prepared. These epoxy-modified mortars are synthesized with various polymer-cement ratios subjected to initial wet/dry curing (WDC) together with long term dry curing (DC). Their self-healing function and hardening effects are evaluated via preloading and drying of the specimens, chemical analysis, and ultrasonic pulse velocity testing. It is demonstrated that 10% of polymer is the best proportion for polymer-cement ratio. Furthermore, the wet/dry curing is established to be superior process for healing hairline cracks present in the mortar. The excellent features of the results suggest that our novel method may constitute a basis for improving the compressive strength and self-healing features of mortars.
h i g h l i g h t s Compressive capacity enhancement in cold-formed steel composite column. Compo... more h i g h l i g h t s Compressive capacity enhancement in cold-formed steel composite column. Composite assembled with ferro-cement jacket and bolts. Three types of bolts with four diameter sizes. Higher column ultimate load capacity with higher wire mesh layers and bolts diameter.
Abstract of Emerging Trends in Scientific Research, 2015
In conventional composite construction for buildings and bridges, Hot-Rolled Steel (HRS) section ... more In conventional composite construction for buildings and bridges, Hot-Rolled Steel (HRS) section is well known to be used. The composite action is usually achieved by using conventional headed stud shear connectors. However, for Cold-Formed Steel (CFS) section, the use of headed stud shear connectors is not feasible as the section is very thin and incapable to be weld. Therefore, a suitable shear connection system of bolt and nut is proposed in this study by varying the size of the bolted shear connectors. This paper presents the prospect of using a bolt and nut as shear connector that could be well-suited with CFS section when integrated in Self-Compacting Concrete (SCC). The experimental test comprised of push-out and was conducted to determine the strength and ductility of the proposed bolted shear connectors as used in composite construction. Eight push-out test specimens of bolted shear connector size consist of M12, M14 and M16 of grade 8.8 were fabricated and tested to failure. The experimental results show that the bolted shear connectors used to possess good shear resistance capacity. Influence of varying the size of the bolted shear connectors was investigated. The results show that the size of bolted shear connectors influenced the ultimate strength capacity of the shear connectors significantly.
This paper describes the results of an ongoing test program to evaluate the performance of polyme... more This paper describes the results of an ongoing test program to evaluate the performance of polymer-modified cement-based mortars for repairing surfaces up to a depth of 75 mm (3 inches) of concrete structures damaged due to exposure to cold climates. Twenty-five selected commercially available polymer-modified products, seven containing styrene butadiene rubber (SBR) and 18 containing acrylics were evaluated. They were compared with a pure cement-based mortar containing 8 percent silica fume with a water/(cement + silica fume) (W/C) ratio of 0.31. All mortars were subjected to physical and mechanical tests. This paper also presents the performance of the three best polymer-modified cement-based mortars (included in the 25 mortars), installed in 1992 on two spillways of a dam in a very severe environment. The six inspections so far have found that these three products are still performing well after an exposure to very low temperatures for a period of four years.
Abstract: Applications such as soil, rock, and oil-well grouting all require enormous amounts of ... more Abstract: Applications such as soil, rock, and oil-well grouting all require enormous amounts of cement and are therefore good examples of areas where high volumes of ground slag or pozzolans such as fly ash could partially replace cement to produce low-cost, ...
The study evaluated the impact of graphene powders used as additives in the recipe of the experim... more The study evaluated the impact of graphene powders used as additives in the recipe of the experimental lime mortar to a mixture ratio of 1:2.5 of NHL3.5 hydraulic lime:fine sand. The content of binder, aggregate and water was kept constant, varying only the amount and the type of the added additives in relation to the amount of natural hydraulic lime NHL3.5. The following five types of experimental mortars were prepared as follows: reference mortar (without additive); mortars containing 1 wt.% GO and 5 wt.% GO powder; mortar with the following GO powders mixture: GO powder functionalized with silver nanoparticles and with fly ash (GO-Ag + GO-fly ash); mortar with the following GO powders mixture: GO with zinc oxide and with titanium oxide (GO-ZnO + GO-TiO2). The influence of the GO-based additive addition on the porosity, surface microstructure, and water sorption coefficient of the mortar samples was evaluated. The antibacterial effect of the mortar samples against three bacterial ...
Schwefel. ‐ Die Struktur und vor allem die i magnetischen Eigenschaften von Mischkristallen der Z... more Schwefel. ‐ Die Struktur und vor allem die i magnetischen Eigenschaften von Mischkristallen der Zusammensetzung (I) werden untersucht.
Proceedings of the Institution of Civil Engineers, Apr 1, 2019
Waste coconut shell (CS) was used to produce nano charcoal ash (NCA) as a potential modifier mate... more Waste coconut shell (CS) was used to produce nano charcoal ash (NCA) as a potential modifier material in an asphalt binder. This study focused on the microstructural and physical properties of NCA. Thermogravimetric analysis and derivative thermogravimetric analysis (TGA/DTA), field emission scanning electron microscopy (FESEM), X-ray fluorescence, particle size analysis (PSA), penetration tests, softening point tests and dynamic shear rheometer (DSR) tests were performed. The TGA/DTA results revealed 490°C to be a suitable CS burning temperature to form carbon and to reduce impurities. The morphology determined by FESEM showed that charcoal CS presents a smooth, porous and irregular shape. The carbon content on the surface of the material was 77•6%, as indicated by energy-dispersive X-ray spectroscopy. PSA showed that the optimum size of the charcoal CS obtained after several grinding cycles was 148 nm. Test results indicated that adding NCA from coconut shell to bitumen improved the binder stiffness up to 47% and significantly increased the softening point up to 12% compared with virgin binder. The DSR test revealed that the optimum size of NCA enhanced the bitumen by increasing the resistance to rutting until a temperature of 76°C was reached, prior to failure at a temperature of 82°C.
"SP-126: Durability of Concrete: Second International Conference, Montreal, Canada 1991"
Erosion by abrasion, cavitation and/or chemical attack in concrete hydraulic structures deteriora... more Erosion by abrasion, cavitation and/or chemical attack in concrete hydraulic structures deteriorates spillways, stilling basins, chutes, slabs and transverse joints, concrete blocks under water gates and any irregular surface subjected to high water flow rate. Countless overlays are commercially available for repairing deteriorated surfaces. However, the essential data provided by manufacturers is very limited and, even if it is available, it is normally limited to room temperature values. This persuaded Canadian Electrical Association to financially support a comprehensive study on commercial overlays, especially from the viewpoint of resistance against erosion and the severe climatic conditions observed in northern parts of Canada. This paper presents laboratory test data on the erosion resistance and durability properties of various types of commercial overlays such as comentitious grouts, polymer-modified cement-based mortars and epoxy mortars.
The intake concrete tunnel at Bersimis-1 generating station is coated with a black sticky substan... more The intake concrete tunnel at Bersimis-1 generating station is coated with a black sticky substance (slime) approximately 5 mm in thickness. Since the tunnel is 12 km long and has an average internal diameter of 9.45 m, the deposit represents a considerable obstacle to the production of electric power. The resulting loss of power generated is estimated to be around 39 MW per year, valued at 71 million dollars. Inspections in 1979, 1981, and 1983 showed that simply cleaning the surfaces would reduce the power losses but the slime built up again after a few years. A thin, smooth protective coating, containing anti-slime agents, compatible with the existing concrete could protect the surfaces against erosion and limit the slime deposit and its harmful effect on power production. The 1993 inspection provided an opportunity both to analyze the concrete, the slime itself, and the water and to experiment with the various methods of cleaning the surface and applying the different coating products. In 1994, 11 other products were selected for the specified characteristics and applied on concrete pipes and installed at two different locations: one consisted of submerged concrete specimens in the Bersimis river and in the second test setup, the products were installed by creating an artificial environment similar to the tunnel conditions using the tunnel water. The results showed that some products do not resist these conditions. Abrasion resistance tests in the laboratory confirmed these observations. One of the eleven products, a polymer-modified cement-based mortar, passed the submersion test and was applied to a small surface area (125 m 2) of the tunnel during a generating station shutdown in 1995. The thickness of the mortar required to cover the walls of the tunnel was between 2 and 3 mm. The total cost of repairing with the mortar was estimated to be between 10 and 11 million dollars. The size of the tunnel, its restricted accessibility, cleaning, ecological disposal of the slime, and the large quantities of material to be applied to cover the entire tunnel added to the complexity of the project.
One of the essential steps for planning solid waste management towards sustainable development is... more One of the essential steps for planning solid waste management towards sustainable development is to reuse solid waste in the construction industry. Coal is one of the world's most important sources of energy, fueling almost 40 % of electricity worldwide. Malaysia is commonly producing electricity through burning millions of tonnes of coal. This process generates around 8.5 Mt of coal ash, which comprised of 80 % Fly Ash (FA), and 20 % Bottom Ash (BA) as waste. The study aims to investigate the workability, compressive strength and leachability of concrete containing BA and FA as replacement of sand and cement. Cement was substituted with 20 % of FA by mass and fine aggregate was replaced with BA at 0, 20, 50, 75 and 100 % in the concrete mix. The results show that the percentage sum of SiO2, Al2O3 and Fe2O3 (the main chemical composition in coal ash) in FA and BA are about 78.82 % and 83.24 %. The leaching test showed that the heavy metal concentrations in leachates are much lo...
h i g h l i g h t s Flow characteristics of ternary blended self-consolidating mortar. Self-conso... more h i g h l i g h t s Flow characteristics of ternary blended self-consolidating mortar. Self-consolidating mortar incorporating palm oil fuel ash (POFA) and pulverised burnt clay (PBC). Effect of high range water reducer (HRWR) on the blend of POFA and PBC. Flow ability of the various mortars with different mix proportion. Addition of a blended POFA and PBC prevented the bleeding of the mortars.
Uploads
Papers by Jahangir Mirza