Title : SELF COMPACTING GROUT AND CONCRETE – HOW IS IT PRODUCED AND WHY IS IT NEEDED?
Authors : Hakim Abdelgader
Publication : 5-9 December 2010
Volume :
Pages : 18-25
Price : 250
Abstract : Using non-traditional concrete in engineering applications such as the construction of nuclear reactor shields, dams, massive under water bridge piers and repairs of building foundations…etc., have been considered as an efficient solution to overcome challenges of limitations of the use of normal conventional concrete. Such new types of concretes which have been developed and produced are completely dissimilar from the conventional concrete in the method of mixing, handling, pouring, consolidation, behaviours, cost etc. Based on the technology of ready-mixed self-compacting concrete (SCC), two types of concrete been introduced and named as: two-stage concrete (TSC) and rock-filled concrete (RFC), where a self-compacted grout (SCG) injected or poured tofill the void space of preplaced or self-compacted aggregate (SCA) or rocks. By other words, TSC (Pre-placed Aggregate) unlike normal concrete (NC), it is made by first placing the coarse aggregate in the formwork and then injectinga grout consisted of sand, cement and water to fill the voids between the aggregate particles. The main benefits of the method are widely appreciated as Low heats of hydration, high compressive strengths and density, economic savings, practically no mass shrinkage, low coefficient of thermal expansion, excellent bond to existing structures. Similarly, the construction technology of RFC mainly consists of two processes: filling the working space with large scale rock mass and pouring the SCC into the pre-packed rock body. Less cement in the composite, which results in less heat of hydration, makes the temperature control of RFC much easier, and this new construction method leads to fast construction speed, high concrete quality and improves the economics and environmental performance of massive concrete structures. This paper illustrates the importance, advantages and special requirements of introducing TSC and RFC to be used in the concrete industry.