Self consolidating concrete properties
Consolidation is the process of inducing a closer arrangement of the solid particles in freshly mixed concrete by reduction of voids.During placement some consolidation is caused by gravity, but in order to ensure that concrete is properly consolidated additional methods are also employed.Concrete, a composite material composed of cement, water, sand, and gravel, the world’s most widely used construction materials.In 2003, more than 110 million metric tons of cement were consumed in the United States (U. Department of the Interior 2004), hence it is important to understand the properties of concrete in order to ensure safe and durable structures.To combat problems caused by improperly vibrated concrete, self consolidating concrete (SCC) was developed at the University of Tokyo in Japan around 1988 by Professor Okamura and his students.Major highlights of the development of SCC is shown in Figure below.The most common method of consolidation is vibration and proper vibration of concrete ensures that the concrete is consolidated around the reinforcement and in the corners of the formwork.
Since its development SCC was widely used in precast industry due to higher powder content necessary to keep the self-compactibility. Maček, AMeden, Carboaluminate phases formation during the hydration of calcite-containing portland cement, Cement Concrete research 7, 2007, pp.551-560. On the other hand, it was not useful to the strength if the strength grade of concrete was high.
The results indicate that there is a tendency of increase in the compressive strength and flexural strength, and the flexural modulus of elasticity of concrete containing silica fume decrease gradually with the increase of fiber volume fraction.
Abstract: Based on the experiment, the splitting tensile strength and axial tensile strength of specified density steel fiber concrete are studied.
Scrivener, Inﬂuence of limestone on the hydration of portland cements, Cement Concrete Research 8, (2008), 848-908. The compressive strength of the concrete in 28 days is 52.8MPa, 46.4.2MPa and 42.6MPa, respectively, higher than that of ordinary concrete.
The concrete was prepared using these aggregates with the water-cement ratio of 0.45, 0.50 and 0.55 respectively.
The fluidity of concrete is attained by adjusted powder content and superplasticiser, no viscosity-modifying admixtures was used. When the content of wastes was appropriate the hollow partition precast with recycled concrete have good physical properties.