the strength of concrete is a function of the proportions of the constituent materials, namely, cement, water, fine and coarse aggregates. the conventional methods used to determine the mix proportions that will yield the desired strength, are laborious, time consuming and expensive. in this paper, a mathematical method based on modified regression theory is formulated for the prediction of con...

this paper deals with the interfacial effects of silica fume (sf) and styrene-butadiene polymer (sbr) on compressive strength of concrete. analyzing the compressive strength results of 32 concrete mixes performed over two water-binder ratios (0.35, 0.45), four percentages replacement of silica fume (0%, 5%, 7.5%, 10%) and four percentages of sbr (0%, 5%, 10%, 15%) were investigated. a mathemati...

The addition of steel fibers into concrete improves the postcracking tensile strength of hardened concrete and hence significantly enhances the shear strength of reinforced concrete reinforced concrete beams. However, developing an accurate model for predicting the shear strength of steel fiber reinforced concrete (SFRC) beams is a challenging task as there are several parameters such as the co...

high strength fresh leachates generated at a new disposal trench, compost plant and partially stabilized leachate of an older trench were characterized in terms of anaerobic degradation at laboratory batch scale at 35oc. fresh leachate had extremely high cod of 66,710 – 89,501 mg/l along with low ph of 4.1-5.9 in contrast to older and therefore partially stabilized leachate with a cod of about ...

a comparison between design codes i.e. aci and aisc-lrfd in evaluation of flexural strength of concrete filled steel tubular columns (cfts) is examined. for this purpose an analytical study on the response of cfts under axial-flexural loading is carried using three-dimensional finite elements with elasto-plastic model for concrete with cracking and crushing capability and elastoplastic kinemati...

the use of methods employed for estimating the strength and toughness of composites reduces the trial-and-error in their design. the strength of interface between reinforcement and matrix and the effective surface of pulled-out particles have great influences on toughness and strength of these composites. in this study, a model was proposed to estimate the interface strength and matrix strength...

a new model is proposed in this research to calculate the longitudinal strengthof unidirectional e-glass reinforced polymer composites exposed to sulfuricacid environment, using a micromechanics model. in the proposed method,it is assumed that the residual strength of the degraded composites under acidic environment can be calculated by knowing the degraded strength properties of the constituen...

The strength of concrete is a function of the proportions of the constituent materials, namely, cement, water, fine and coarse aggregates. The conventional methods used to determine the mix proportions that will yield the desired strength, are laborious, time consuming and expensive. In this paper, a mathematical method based on modified regression theory is formulated for the prediction of con...