Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : splitting tensile


Enhancing of Crushed Brick Aggregate Concrete by Adding Alkalis

S.A. Hameed

Engineering and Technology Journal, 2017, Volume 35, Issue 6, Pages 554-559

The process of recycling the waste of construction materials increased in most countries in the world, because of the huge quantities of waste materials result from demolition that will effect of the environment and increase landfills. This research aims to examine the recycle clay bricks aggregate in concrete mix instead of coarse aggregate and to study the effect of alkalis on this kind of concrete by partial replacement of recycle clay bricks aggregate (RCBA) instead of natural coarse aggregate. A cubic, cylinder and prisms specimens were casted to estimate the mechanical properties like dry and wet density, compressive strength, splitting tensile strength and modulus of rupture for this concrete. The results shows the increasing of RCBA will decrease the compressive strength, splitting tensile strength and modulus of rupture but the addition of alkalis with 20% of mix water will increase the workability and reduce the mix water and increase the wet and dry densities, and reduce the compressive strength and splitting tensile strength and the modulus of rupture.

Fresh and Hardened Properties of Steel Fiber-Reinforced Self-Consolidating Concrete

Maan S. Hassan; Iqpal N. Gorgis; Aymn H. Ali

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 1213-1225

The main aim of this research is to study the effect of using hooked end steel fiber on the fresh and hardened properties of self-consolidating concrete. The experimental work includes two stages. First stage involved conducting several trial mixes and then choosing the one that conform tothe international standards in terms of fresh properties. Second stage concerned on the compressive, flexural tensile and splitting tensile strengths evaluationof the selected mixes, at 28 and 90 days.Four concrete mixes were obtained and evaluated. They were similar in mix proportions and differ only in volume fractions of steel fibers incorporated: 0%, 0.5%, 1%, and 1.5%.
Results showed that adding hooked steel fibers adversely affect SCC workability and thus more dosage of SP should be added to stay within the standard limits. Similar to conventional HPC, the presence of steel fibers with SCC provide slight increase in compressive strength at 28 days, (up to 11%), while significant enhancement in tensile properties were observed (up to 68% and 80% for splitting and flexural strength respectively). Flexural strength (i.e. modulus of rapture) was generally still higher than splitting testing results in a decreasing order. This order is still applicable in SCC even with the presence of steel fibers.