Sohaib Naseer - Academia.edu (original) (raw)
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University of Engineering and Technology Taxila, Pakistan
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Papers by Sohaib Naseer
Concrete is the most extensively used in large-scale constructions where strength, workability, a... more Concrete is the most extensively used in large-scale constructions where strength, workability, and durability are main requirements. Engineers are continually pushing the limits upward to improve its performance with the help of innovative chemical admixtures and supplementary cementitious materials. Nowadays, most concrete mixtures contain supplementary cementitious material which forms part of the cementitious component. The main benefits of SCMs are their ability to replace certain amount of cement and still able to display cementitious property, thus reducing the cost of using Portland cement.
This paper investigated the properties of concrete by partial replacement of cement with 5, 10, 15% and 20% of silica fume by weight. Compressive strength of concrete specimens, were compared with concrete specimens, with no silica fume, at 7, 14, 28, 56 and 90 day’s age. A constant water cement ratio of 0.35 was maintained and to compensate its workability, super-plasticizer was used.
Specimens which included both 6 inches diameter cylinders and 4 inches cubes were casted and tested in accordance to ASTM standards. Test results indicated improvement, in the compressive strength properties of cube samples by the inclusion of silica fume as a partial replacement of cement at a replacement level of 10% but showed totally opposite behavior in case of cylinders.
The sustainable practices are based on the principles of resource conservation, life cycle costin... more The sustainable practices are based on the principles of resource conservation, life cycle costing and human friendly design. The resource conservation focuses on minimum use of material, energy and water resources, which in turn relies on reducing, reusing and recycling (3R) of resources. Disposal of construction wastes pose major challenge to the municipal administration in the developing countries of Asia Pacific region. The fast urbanization and rapid construction in these regions are producing a huge burden on the natural resources. At the same time old buildings and infrastructure are also enhanced, upgraded and modernized to accommodate the new technological demands of growing populations. This has led to generation of substantial volume of construction wastes in the developing countries of Asia. The transportation and disposal of construction wastes require additional resources, which severely affect other projects of the municipal authorities.
There are many options for the disposal of construction wastes. One of the options to reduce the burden of such construction wastes is to utilize such wastes as construction ingredients such as aggregates and sands for concrete. The reuse of such aggregates in the concrete would reduce the disposal costs of construction wastes at one hand and burden on natural resources in terms of resource harvesting on the other hand.
In this research work the construction solid wastes collected from the municipal sources have been segregated, graded and utilized as aggregates in cement concrete. Various mix design of concrete have been prepared and tested in the laboratory to check it compressive strength and suitability for the construction purposes. The concrete cylinders and cubes cast from the recycled aggregates were tested in the lab and failure patterns of these samples were observed closely.
The results have shown that there are ample opportunities of re-using the solid wastes as aggregates and sands in the concrete and new constructions in Asia Pacific region
The Seismic Provisions (2007) have been included in the Pakistan Building Code after the unusual ... more The Seismic Provisions (2007) have been included in the Pakistan Building Code after the unusual and unprecedented Kashmir earthquake of 2005. The provisions are based on Equivalent Lateral Force (ELF) Method where more emphasis has been laid over improving the detailing of reinforced members to induce ductility in their behavior. This assumption many times leads to overdesign and increased cost of the construction. The Performance Based Design (PBD) is instead based on advanced analysis on micro level for the specific site conditions. This brings more precision and the performance of the building more closer to the real behavior of the building during earthquakes. In this research work an existing under construction building has been analyzed on both the Seismic provisions of Pakistan Building Code and Performance based design to check the suitability of both the methods. The results have shown that the ESF method overestimates the base shear at one hand and the negative moments are underestimated as compared to PBD. This can lead to major damage to the building in case of earthquake. The PBD can also bring more economy and real picture
Concrete is the most extensively used in large-scale constructions where strength, workability, a... more Concrete is the most extensively used in large-scale constructions where strength, workability, and durability are main requirements. Engineers are continually pushing the limits upward to improve its performance with the help of innovative chemical admixtures and supplementary cementitious materials. Nowadays, most concrete mixtures contain supplementary cementitious material which forms part of the cementitious component. The main benefits of SCMs are their ability to replace certain amount of cement and still able to display cementitious property, thus reducing the cost of using Portland cement.
This paper investigated the properties of concrete by partial replacement of cement with 5, 10, 15% and 20% of silica fume by weight. Compressive strength of concrete specimens, were compared with concrete specimens, with no silica fume, at 7, 14, 28, 56 and 90 day’s age. A constant water cement ratio of 0.35 was maintained and to compensate its workability, super-plasticizer was used.
Specimens which included both 6 inches diameter cylinders and 4 inches cubes were casted and tested in accordance to ASTM standards. Test results indicated improvement, in the compressive strength properties of cube samples by the inclusion of silica fume as a partial replacement of cement at a replacement level of 10% but showed totally opposite behavior in case of cylinders.
The sustainable practices are based on the principles of resource conservation, life cycle costin... more The sustainable practices are based on the principles of resource conservation, life cycle costing and human friendly design. The resource conservation focuses on minimum use of material, energy and water resources, which in turn relies on reducing, reusing and recycling (3R) of resources. Disposal of construction wastes pose major challenge to the municipal administration in the developing countries of Asia Pacific region. The fast urbanization and rapid construction in these regions are producing a huge burden on the natural resources. At the same time old buildings and infrastructure are also enhanced, upgraded and modernized to accommodate the new technological demands of growing populations. This has led to generation of substantial volume of construction wastes in the developing countries of Asia. The transportation and disposal of construction wastes require additional resources, which severely affect other projects of the municipal authorities.
There are many options for the disposal of construction wastes. One of the options to reduce the burden of such construction wastes is to utilize such wastes as construction ingredients such as aggregates and sands for concrete. The reuse of such aggregates in the concrete would reduce the disposal costs of construction wastes at one hand and burden on natural resources in terms of resource harvesting on the other hand.
In this research work the construction solid wastes collected from the municipal sources have been segregated, graded and utilized as aggregates in cement concrete. Various mix design of concrete have been prepared and tested in the laboratory to check it compressive strength and suitability for the construction purposes. The concrete cylinders and cubes cast from the recycled aggregates were tested in the lab and failure patterns of these samples were observed closely.
The results have shown that there are ample opportunities of re-using the solid wastes as aggregates and sands in the concrete and new constructions in Asia Pacific region
The Seismic Provisions (2007) have been included in the Pakistan Building Code after the unusual ... more The Seismic Provisions (2007) have been included in the Pakistan Building Code after the unusual and unprecedented Kashmir earthquake of 2005. The provisions are based on Equivalent Lateral Force (ELF) Method where more emphasis has been laid over improving the detailing of reinforced members to induce ductility in their behavior. This assumption many times leads to overdesign and increased cost of the construction. The Performance Based Design (PBD) is instead based on advanced analysis on micro level for the specific site conditions. This brings more precision and the performance of the building more closer to the real behavior of the building during earthquakes. In this research work an existing under construction building has been analyzed on both the Seismic provisions of Pakistan Building Code and Performance based design to check the suitability of both the methods. The results have shown that the ESF method overestimates the base shear at one hand and the negative moments are underestimated as compared to PBD. This can lead to major damage to the building in case of earthquake. The PBD can also bring more economy and real picture