An Experimental Investigation on Metakaolin Modified Concrete Paver Blocks

Abstract

Concrete paver blocks are special pre-cast pieces of concrete blocks of non-interlocking or interlocking types, commonly used in exterior landscaping pavement applications. Properly designed and constructed paver blocks give excellent performance at locations where conventional pavement systems have lower service life due to a number of environmental, geological constraints. But with the use of high performance concrete they can be designed to sustain light, medium, heavy and very heavy traffic conditions under any constraints.

Modern concrete can be modified with addition of mineral admixtures which refine the microstructures of the concrete and enhance its physical properties and durability. Metakaolin, produced by controlled thermal treatment of kaolin, can be used as a concrete constituent, since it has pozzolanic properties. It is a highly efficient Pozzolana and react rapidly with the excess calcium hydroxide resulting from OPC hydration by a pozzolanic reaction, to produce calcium silicate hydrate and calcium alum inosilicate hydrates.

Hence the objective of the present work was to evaluate the performance of concrete modified with Metakaolin for paver blocks for use in pavements and other application areas. As compressive, flexural strengths and water absorption are the most significant properties for concrete paver blocks the same have been studied for various concrete mixes with varying percentages of Metakaolin.

Metakaolin was used as partial replacement of cement in the study and three percentages 5%.10% and 15% were adopted for determination of compressive strength, flexural strength and water absorption of zigzag, dumbel and I shape paver blocks. The mix with 10% replacement was found to give maximum compressive, flexural strength and minimum water absorption for all types of paver blocks. To validate the above conclusion XRD, FESEM and EDS analysis of the MK modified mixes were done and found that addition of MK to concrete made microstructure very dense, thereby improving its properties