The presented work investigates the effect of addition admixtures (superplasticizer and polymer) to Chopped Worn-Out Tire concrete as a partial replacement of cement weight. Superpasticizer was addition by 4% and polymer (SBR) by 15%. The Chopped Worn-Out Tire (Ch.W.T.) addition to reference concrete with the three proportions as a Partial Replacement Ratio (PRR) of (25,25),(20,30),and (30,20) by volume of (sand and gravel) respectively. Three mixes were selected with above PRR for each type of admixture in additional to three mixes for Ch.W.T. concrete without admixtures and three reference mixes with admixtures without Ch.W.T. Thus, twelve mixes could be used in this investigation. Compressive strength and modulus of elasticity (static and dynamic) were tested. The test results indicated that the use of admixture led to significant improvement in concrete properties in general. Superplasticizer gave best results comparative with polymer, for example at 28 day the compressive strength of superplasticizer Ch.W.T. concrete Csp25,25 was 32.5 MPa, while compressive strength of polymer modified Ch.W.T. concrete CB25,25 was 28 MPa and compressive strength of Ch.W.T. concrete C25,25 was 21.2 MPa.
The aim of this paper is to study experimentally the effect of steel fibers content on the modulus of elasticity of High Performance concrete HPC in different curing age. The results showed that adding steel fibers to HPC led to a considerable improvement in static and dynamic modulus of elasticity where at 90 day water curing the percentages of increasing in static modulus of elasticity of High Performance Steel Fiber Concrete HPSFC relative to HPC were 8.2%, 9.98%, and 11.88% at 0.5%, 1%, and 1.5% steel fibers by total concrete volume, respectively. While, the improvement of dynamic modulus of elasticity of HPSFC relative to HPC at 28 day were 8.09%, 10.7%, and 11.07% % at 0.5 %, 1 %, and 1.5 % respectively.