Properties of sustainable cement mortars containing high volume of raw diatomite

Abstract

This paper presents the results of a study on properties of cement mortars containing high volume of raw diatomite powder as replacement of cement. The use of high volume of pozzolanic powders decreases the demand for cement in the construction industry and thus reduces the cost of concrete production and lessens the environmental pollution caused by the CO2 emission from the cement factories. The aim of this study is to investigate key properties of environmental-friendly cement mortars using raw diatomite powder as replacement of cement in different contents. In this study, cement mortars containing four different contents of raw diatomite powder as replacement of cement (0, 15, 30 and 40 by weight of total cementitious material) are examined. The flowability of cement mortars was observed through flow table test. The compressive strength and direct tensile strength were measured at 3, 7, 28 and 91 days as strength properties. Water absorption and pulse velocity tests were investigated for various cement mortar mixtures at 28 days as transport properties and durability indexes. An environmental impact assessment was also applied on all cement mortar mixes based on eco-balance method to quantify and evaluate the environmental impact of partially replacing cement by raw diatomite powder. Test results indicated that diatomite powder can be used as replacement of cement up to 40% without significant loss in compressive strength along with an improvement in tensile strength and transport properties of cement mortars, at the later aging times. The experimental results on strength and transport properties represent a very effective and successful use of high volume raw diatomite powder to produce an environmental-friendly and affordable cement-based material. Sustainability assessment shows a significant reduction in environmental impact of mortars containing high volume of raw diatomite powder.