Papers by Ola A D E L Qasim
IOP Conference Series: Materials Science and Engineering, 2019
Concrete is an important, widely used material in modern-day construction. Structural planners st... more Concrete is an important, widely used material in modern-day construction. Structural planners steadily attempt different strategies and designs that will advance their constructions further aesthetically agreeable, functionally practical, and cost saving. Historically, the development in constructions depended greatly upon the properties of engineering substances. A different set of material with superior characteristics regularly results in a revolution in constructions; this is true for steel structures and concrete structures as well. However, the design of structures with innovative materials, such as RPC, cannot hold out with traditional design certificates that do not hold well with nontraditional materials. Ultra-High-Performance Concrete is considered with concern to its cost-effectiveness and sustainability. In several countries, concrete having a compressive strength of higher than 80MPa cannot be employed because current codes limit the additional strength. Accordingly, considerable performance on introducing an innovative design of standards and codes for RPC constructions necessity be managed to get used of the substances possibly. Further cost improvements with RPC superior traditional concrete involve controlled building times and extended usable floor space or overhead clearance predicted extended service life and lower maintenance cost advantages. This investigation pointed to describe the variation within the cost of traditional concrete material and Reactive Powder Concrete material.
IOP Conference Series: Materials Science and Engineering, 2019
The principal of using the material regarding to its strength and durability within the service l... more The principal of using the material regarding to its strength and durability within the service life of the structure while reducing the energy and resource consumption due to the construction and operation of a structure is called sustainable structural engineering, it is enlargement of sustainable construction in the future regarding to the standard concrete. Reinforced concrete slabs (solid and with openings) represents one of the common essential fundamental elements and are generally employed in many kinds of engineering constructions and applications. Reactive Powder Concrete (RPC) is a new ultra-high-performance concrete which tends to exhibit superior properties, high durability, and long-term stability, in form of superplasticizer, cement mixture with silica fume, steel fiber (of varying types, sizes, and geometries), and the fine glass of (<600 mµ). Ten reinforced concrete slabs with different variables (opening shapes, opening locations, opening size and steel fiber content) were casted and tested to study the behavior of RPC material in flexure in term of deflection, concrete strains, and ultimate loads. RPC has better performance in term of flexural behavior, cracking control and deformation control. Preliminary investigation tests were conducted to study the fresh and hardened properties of concrete. The results show that increase in steel fiber content leads to an increase in the failure load and consequently increase in maximum deflection and the flexural toughness increases.
https://iopscience.iop.org/article/10.1088/1757-899X/518/2/022077, 2018
Recent trends in concrete technology have been towards high-strength concrete and ultra-high stre... more Recent trends in concrete technology have been towards high-strength concrete and ultra-high strength concrete with a low water-cement ratio. However, these high and ultra-high strength concretes have some problems. One of the problems is early-age cracking due to autogenous shrinkage. This study presents the results of an experimental investigation carried out to evaluate the autogenous shrinkage of high and ultra-high strength concrete. Main ideas on autogenous shrinkage are based on the use of ordinary Portland cement, but it has already become apparent that mineral admixtures and fibers change the behavior significantly. Variables were taken to study its effect on shrinkage like (effects of water/cement ratio, cement content, coarse aggregate content, silica fume percentage and steel fiber). From the test results, it is concluded that the autogenous shrinkage strain of mixes increases with decrease w/c ratio and decrease with increasing w/c ratio and concrete with the higher value of cement content, shows greater amounts of shrinkage. The autogenous shrinkage strain increases with decreasing of the coarse aggregate content. The additions of 10-20 % of silica fume to the mix increase the autogenous shrinkage strains of concrete specimens. The autogenous shrinkage decreased gradually with the increase of steel fiber content.
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Papers by Ola A D E L Qasim