Study of the shear strength equations of reinforced concrete beams with and without steel fibers and suggestion an equation to the case of lightweight concrete

This paper presents the shear behavior of lightweight concrete beams without shear reinforcement produced by scoria aggregates. A total of nine beams were tested under four-point loads, including three lightweight concrete beams without steel fibers and six steel fiber reinforced lightweight concrete beams.

Study the effect of cement content on the lightweight concrete properties and the extent of compliance with the requirements of structural lightweight concrete according to the code ACI 213R-03

This study presents definition of the types of lightweight concrete and some studies, which use the volcanic scoria aggregates to produce structural lightweight concrete. Several concrete mixes were designed, and different tests were performed to determine its properties.

Mechanical properties of steel fiber reinforced lightweight concrete

Thepaper studies the mechanical properties ofsteel fibers reinforced lightweight concrete.This kind of concrete is produced by usingscoria aggregateswhich can be found abundantly in Syria. Thelightweight concrete mixeswere designed for three different percentage of steel fibers (0, 0.5, 0.75)%. Different tests were performed to determine mechanical properties of product concrete such as compressive strength, elasticity modulus, splitting tensile strengthand flexural strengthalso; the stress–strain diagram of produced lightweight concrete was established under compression. The results showedanincrease of the compressive, splitting tensile and flexural strengths reach up 16.9%, 25.6%, and 53.6% respectivelywhen the steel fibers were used. Also the results indicated the importance of using the steel fibers to improve the performance of concrete and change its brittle behavior to ductile behavior.

Producing lightweight concrete by using Scoria aggregates Available in Syria and study its mechanical and physical properties

This research deals with producing structural lightweight aggregates concrete (the density is less than 1920kg/m3 and compressive strength is more than 17.2Mpa according to ACI 213R-03) by using scoria aggregates. Several concrete mixes have been designed with different proportions of scoria aggregates. The cement content (c=450 kg/m3), the ratio (w/c = 0.36) were kept constant in all the mixes. Different tests were performed to determine some properties of product concrete such as density, compressive strength and splitting tensile strength. The density of product concrete was in the range of (1752-1917 kg/m3), compressive strength was in the range of (22.2-32.8Mpa), and the splitting strength was in the range of (2.3-3.2Mpa). The study demonstrated the possibility of production concrete achieved the Requirements of the American code ACI 213R-03 for structural lightweight concrete.

Contribution in Study of some physical and mechanical properties of foamed concrete

foamed concrete is a concrete made by cement slurry mixed with foaming agent, so that foamed concrete is lighter than conventional concrete. The objectives of this study is to produce this kind of concrete, and to study some of its physical and mechanical properties. Mix design of concrete was made for four required densities (1000, 1300,1600,1900 kg/m3), cement content of 350 kg/ m3, and water to cement ratio equal to 0.5. Different tests were performed to determine some properties of product concrete such as density, compressive strength and splitting tensile strength. The results demonstrated the possibility of production foamed concrete with wide range of density and strength. The oven dry density of foamed concrete was in the range of (870-1773 kg/m3) , compressive strength was in the range of (2.95-16.2 Mpa ), and the splitting strength was in the range of (0.32-1.76Mpa).