Muhammad Akram Tahir - Academia.edu (original) (raw)

Papers by Muhammad Akram Tahir

Research paper thumbnail of Interfacial Performance between Repairing Mortars and Substrate Lime: Bond Strength and Carbonation

Journal of Materials in Civil Engineering

Research paper thumbnail of Physico-mechanical performance of lightweight geopolymer foam aggregates developed by geopolymerization through microwave-oven irradiations

Journal of King Saud University - Engineering Sciences, 2021

Abstract Climatic change and global warming are pushing researchers to develop waste-based altern... more Abstract Climatic change and global warming are pushing researchers to develop waste-based alternatives to cement and conventional concrete which would have low embodied-energy and operational-energy due to better insulation properties. In this context, the current study presents the production of ultra-lightweight geopolymer foam aggregate utilizing coal fly-ash. Fly-ash was activated by two alkaline activators, sodium hydroxide (NaOH) and sodium silicate (Na2SiO3), and Na2SiO3 performed as foaming agent as well. Sodium bicarbonate (NaHCO3) was also used as an additive for geopolymer hardening and early strength gain. A novel curing method, microwave-oven curing, was practiced as an alternative to conventional energy and time-intensive curing techniques to promote rapid strength development and sustainability of materials and technology. The physico-mechanical performance (morphology, expansion, density, specific gravity, water absorption, strength against compression and impact loading) of manufactured aggregates was examined for pertinent use to formulate ultra-lightweight foam concrete; and the properties were also compared with natural as well as synthetic lightweight aggregate. Results indicated that manufactured aggregates experienced physico-mechanical properties that would be suitable to design lightweight concrete both for structural and insulation purposes. Satisfactory results of experimentation also confirmed the potential of microwave-oven curing to replace conventional curing techniques to realize economical, energy-efficient, and eco-efficient manufacturing of artificial aggregate.

Research paper thumbnail of Evaluation of Concrete Compressive Strength by incorporating Used Foundry Sand

The main objective of this study was to evaluate the compressive strength of concrete by utilizin... more The main objective of this study was to evaluate the compressive strength of concrete by utilizing three types of used foundry sand; with bentonite clay, with sodium silicate & with phenolic resin as partial replacement of fine aggregates. To accomplish the research an experimental program was conducted in which ten concrete mixtures were casted, by keeping all other parameters for concrete proportioning as constant and only change made was in the amount of fine aggregates. Ten, Twenty and Thirty percent replacement level of river sand by used foundry sands was maintained in this study. All fine aggregates were selected after achieving desired physical and chemical tests. Workability, compressive strength and modulus of elasticity were measured and compared with the conventional concrete termed as control mixture. It was observed that workability increased with replacement levels. The cubes were crushed at 7, 28 and 63 days of standard moist curing. The compressive strength of all c...

Research paper thumbnail of Influence of organic agents to compressive strength of cement mortar

Construction and Building Materials, 2018

Research paper thumbnail of Performance of Pozzolanic Concrete Using Different Mineral Admixtures

Research paper thumbnail of Seismic evaluation of equipment supporting structures

ABSTRACT: Industrial buildings are commonly subjected to forces induced by machine vibrations, ea... more ABSTRACT: Industrial buildings are commonly subjected to forces induced by machine vibrations, earthquake and wind loads. There are number of equipments which have vibrating actions and at the same time tall enough to withstand the wind and earthquake ...

Research paper thumbnail of Development of Local Bagasse Ash as Pozzolanic Material for Use in Concrete

Pakistan Journal of Engineering and Applied Sciences, 2016

Concrete is one of the extensively used materials in construction industry. General construction ... more Concrete is one of the extensively used materials in construction industry. General construction uses ordinary Portland cement, however for specialized projects specific properties of concrete are tailored using different pozzolans. Sugarcane bagasse ash is abundantly available in Pakistan as being obtained from sugar mills which uses sugarcane bagasse as fuel. This research is focused to determine the maximum pozzolanic activity of sugarcane bagasse ash. Raw bagasse ash was calcined at temperatures of 500, 600 and 700 degree Celsius for 1, 2 and 3 hours heating duration. ASTM C 618 and C 311 were used to determine the suitability of sugarcane bagasse ash for its pozzolanic activity. It was found that maximum pozzolanic activity is achieved at a temperature of 500 degree Celsius for 1 hour heating duration and same was verified by X-ray diffraction analysis of calcined sugarcane bagasse ash

Research paper thumbnail of Interfacial Performance between Repairing Mortars and Substrate Lime: Bond Strength and Carbonation

Journal of Materials in Civil Engineering

Research paper thumbnail of Physico-mechanical performance of lightweight geopolymer foam aggregates developed by geopolymerization through microwave-oven irradiations

Journal of King Saud University - Engineering Sciences, 2021

Abstract Climatic change and global warming are pushing researchers to develop waste-based altern... more Abstract Climatic change and global warming are pushing researchers to develop waste-based alternatives to cement and conventional concrete which would have low embodied-energy and operational-energy due to better insulation properties. In this context, the current study presents the production of ultra-lightweight geopolymer foam aggregate utilizing coal fly-ash. Fly-ash was activated by two alkaline activators, sodium hydroxide (NaOH) and sodium silicate (Na2SiO3), and Na2SiO3 performed as foaming agent as well. Sodium bicarbonate (NaHCO3) was also used as an additive for geopolymer hardening and early strength gain. A novel curing method, microwave-oven curing, was practiced as an alternative to conventional energy and time-intensive curing techniques to promote rapid strength development and sustainability of materials and technology. The physico-mechanical performance (morphology, expansion, density, specific gravity, water absorption, strength against compression and impact loading) of manufactured aggregates was examined for pertinent use to formulate ultra-lightweight foam concrete; and the properties were also compared with natural as well as synthetic lightweight aggregate. Results indicated that manufactured aggregates experienced physico-mechanical properties that would be suitable to design lightweight concrete both for structural and insulation purposes. Satisfactory results of experimentation also confirmed the potential of microwave-oven curing to replace conventional curing techniques to realize economical, energy-efficient, and eco-efficient manufacturing of artificial aggregate.

Research paper thumbnail of Evaluation of Concrete Compressive Strength by incorporating Used Foundry Sand

The main objective of this study was to evaluate the compressive strength of concrete by utilizin... more The main objective of this study was to evaluate the compressive strength of concrete by utilizing three types of used foundry sand; with bentonite clay, with sodium silicate & with phenolic resin as partial replacement of fine aggregates. To accomplish the research an experimental program was conducted in which ten concrete mixtures were casted, by keeping all other parameters for concrete proportioning as constant and only change made was in the amount of fine aggregates. Ten, Twenty and Thirty percent replacement level of river sand by used foundry sands was maintained in this study. All fine aggregates were selected after achieving desired physical and chemical tests. Workability, compressive strength and modulus of elasticity were measured and compared with the conventional concrete termed as control mixture. It was observed that workability increased with replacement levels. The cubes were crushed at 7, 28 and 63 days of standard moist curing. The compressive strength of all c...

Research paper thumbnail of Influence of organic agents to compressive strength of cement mortar

Construction and Building Materials, 2018

Research paper thumbnail of Performance of Pozzolanic Concrete Using Different Mineral Admixtures

Research paper thumbnail of Seismic evaluation of equipment supporting structures

ABSTRACT: Industrial buildings are commonly subjected to forces induced by machine vibrations, ea... more ABSTRACT: Industrial buildings are commonly subjected to forces induced by machine vibrations, earthquake and wind loads. There are number of equipments which have vibrating actions and at the same time tall enough to withstand the wind and earthquake ...

Research paper thumbnail of Development of Local Bagasse Ash as Pozzolanic Material for Use in Concrete

Pakistan Journal of Engineering and Applied Sciences, 2016

Concrete is one of the extensively used materials in construction industry. General construction ... more Concrete is one of the extensively used materials in construction industry. General construction uses ordinary Portland cement, however for specialized projects specific properties of concrete are tailored using different pozzolans. Sugarcane bagasse ash is abundantly available in Pakistan as being obtained from sugar mills which uses sugarcane bagasse as fuel. This research is focused to determine the maximum pozzolanic activity of sugarcane bagasse ash. Raw bagasse ash was calcined at temperatures of 500, 600 and 700 degree Celsius for 1, 2 and 3 hours heating duration. ASTM C 618 and C 311 were used to determine the suitability of sugarcane bagasse ash for its pozzolanic activity. It was found that maximum pozzolanic activity is achieved at a temperature of 500 degree Celsius for 1 hour heating duration and same was verified by X-ray diffraction analysis of calcined sugarcane bagasse ash