–Flyash based geopolymer concrete is introduced in 1979 by Davidovits to reduce the use of OPC in concrete. Geopolymer is an inorganic alumino-hydroxide polymer synthesized form predominantly silicon and aluminum materials of geological origin and by product materials such as flyash (with low calcium). In this paper an attempt is made to study strength properties of geopolymer concrete using lo...

This paper presents the results of a fundamental study to expand the applicability of the current AASHTO LRFD Bridge Design Specifications for concrete strength up to 18 ksi for reinforced and prestressed concrete members in flexure and compression. A total of 321 specimens were tested to determine the material properties of three high-strength concrete mixtures having target compressive concre...

The aim of the work reported in this article was to investigate the effects of medium temperature and industrial by-products on the key hardened properties of high performance concrete. Four concrete mixes were prepared based on a water-to-binder ratio of 0.35. Two industrial by-products, silica fume and Class F fly ash, were used separately and together with normal portland cement to produce t...

The present Experimental investigation is to study the Mechanical Properties of the Fly ash concrete reinforced with steel fibers. The concrete composite comprises of steel fibers in different percentages and partial replacement of cement in different proportions. Steel fibers varied from 0%, 0.5%, 1% and 1.5% by weight of cement and replacement of fly ash varied from 0%, 10%, 20%, 30% and 40% ...

Cement concrete is a complex mixture of different materials. Behaviour of concrete depends on its mix proportions and constituents when it is subjected to elevated temperatures. Principal effects due to elevated temperatures are loss in compressive strength, loss in weight or mass, change in colour and spall of concrete. The experimental results of normal concrete and high strength concrete sub...

Structural design deeply involves material strengths, which are obviously affected by uncertainty. As far as the material “concrete” is concerned, building codes (Italian codes, Eurocodes, ACI regulations) typically state that it should be identified and classified by means of its conventional characteristic uniaxial compressive cubic strength at 28 days. Although the fundamental importance of ...

Ultrasonic pulse velocity technique is one of the most popular non-destructive techniques used in the assessment of concrete properties. However, it is very difficult to accurately evaluate the concrete compressive strength with this method since the ultrasonic pulse velocity values are affected by a number of factors, which do not necessarily influence the concrete compressive strength in the ...

Currently, building industry uses non-destructive testing methods primarily for evaluation of concrete quality. Efficiency of ultrasonic pulse method (UPM) was proved in order to determine compressive strength of solid bricks (concrete, calcium silicate and burnt ones). Parameters obtained from UPM testing (such as ultrasonic pulse velocity, dynamic modulus of elasticity) are affected by shape/...

By increasing the demolition of old concrete structures and the interest of civil industries to consume cheaper materials, using Recycled Concrete Aggregate (RCA) can cause environmental protection and decrease the construction costs. On the other hand, the high potential of Recycled Aggregate Concrete (RAC) in concrete industry was established by extensive experimental researches were performe...

a reinforced concrete member in which the total span or shear span is especially small in relation to its depth is called a deep beam. in this study, a new approach based on the adaptive neural fuzzy inference system (anfis) is used to predict the shear strength of reinforced concrete (rc) deep beams. a constitutive relationship was obtained correlating the ultimate load with seven mechanical a...