Properties of blended cement using metakaolin and hydrated lime

Abstract

Thermal activation of Ga'ara kaolin is used to produce a good quality metakaolin. Portland cement clinker is ground and blended with 3% gypsum. In this study, two types of mixes are made: the first using 10% hydrated lime and different percentages of metakaolin as replacement by weight of the blended cement; in the second type, only metakaolin is used, without hydrated lime, in mixes as a replacement by weight of the blended cement. The aim of this study is to make a new type of environmentally friendly, blended cement with good fresh and hardened properties. Energy savings can be achieved by using materials produced as industrial by-products (metakaolin, hydrated lime). The compressive strength is 42·1 MPa for the mix with 12% metakaolin and 0% hydrated lime, and 38·8 MPa for 12% metakaolin with 10% hydrated lime, as compared to the reference mix value of 37·9 MPa at age 90 d. Blended cement can be made with 86% Portland cement fineness, adding 22% metakaolin + hydrated lime as a replacement by weight of the blend, to give almost the same compressive strength as the reference mix, with excellent soundness properties. This could reduce the annual production of cement, as well as the associated emission of gaseous pollutants from factories during the cement production process.

Nanoprocessing of Industrial Rejects for Controlling Operational Energy of Buildings

“…Pozzolanicity of principal raw material before and after milling was carried out using various pozzolanicity methods: (i) pozzolanic activity index [44][45][46][47], (ii) electrical conductivity [48][49][50], and (iii) Chapelle activity [44,[51][52][53][54]. Pozzolanic activity index (PAI) was evaluated as per the procedure provided in IS 2250:1981. e sample blocks were prepared by replacing 35% (by volume) of OPC with the selected industrial rejects, i.e., GBFS.…”

Editorial

“…The results indicate that the total hydration heat release is increased with the addition of all three elements, with the addition of strontium oxide yielding the highest heat release. Ismael and Ghanim (2015) investigate fresh and hardened properties of blended cements that contain metakaolin or a combination of metakaolin and hydrated lime. An optimum mix of 22% by weight of cement replacement (12% metakaolin and 10% hydrated lime) produces a blend with a reduced setting time and almost the same compressive strength in comparison to a control mix without cement replacement.…”