Use of GGBS in Manufacturing of Solid Concrete Blocks

Abstract

Concrete blocks are produced in large variety of sizes either solid or hollow, dense or lightweight, air cured or steam cured, load bearing or non-load bearing can be produced manually or with the help of machines. Proportioning the mix components for a concrete masonry unit is an important step in producing high-quality units, otherwise it leads to either uneconomical or poor quality. Hence, an attempt was made to address these issues. Although solid concrete blocks are being used abundantly, there are no proper guidelines for the mixture proportioning. Blocks can be used for different purposes like construction of load-bearing walls as well as non-load bearing walls. There has to be proper guidelines to manufacture these blocks in a consistent manner. Blocks produced these days are purely based on experience of the operator or the laborers working at casting yards, which affects the quality of these blocks. Also, there are no proper guidelines for utilizing either mineral or chemical admixtures in the manufacturing of concrete blocks. Sometimes either excess amount or lesser amount of cement in the manufacturing is usually observed, which can be avoided when proper guidelines are provided. Otherwise this leads to an uneconomical mix or affects the quality of the blocks. An effort to provide guidelines for the proportioning of solid concrete blocks was made. Optimum mix for the manufacturing of solid concrete blocks is mix with a cement content of 150 kg/m3. Mineral admixtures can be used in the manufacturing of solid concrete blocks. However, GGBS has shown very effective in replacement of cement without compromising the quality of the solid blocks. Air-entraining admixtures do not serve their purpose, but plasticizers can be used to reduce w/c for better finish.