Volume 9 • Issue 1 • 1000331 J Civil Environ Eng, an open access journal ISSN: 2165-784X Danso and Adu, J Civil Environ Eng 2019, 9:1 Research Article Open Access J o u r n a l o f C i v i l & E n vi r o n m e nt a l E n g i n e e r i n g ISSN: 2165-784X Journal of Civil & Environmental Engineering Characterization of Compressed Earth Blocks Stabilized with Clay Pozzolana Danso H* and Adu S Department of Construction and Wood Technology, University of Education Winneba, Kumasi, Ghana Abstract The high cost of cement and its greenhouse effect on the environment have led to the use of alternative building materials in the production of block and bricks. This study seeks to investigate the properties of compressed earth blocks (CEBs) stabilized with clay pozzolana. CEBs of size 290 × 140 × 100 mm were prepared with 0, 10, 20 and 30% weight of clay pozzolana. The CEBs were compressed at a constant pressure of 5 MPa and cured. The blocks, after 7, 14, 21 and 28 days of curing were tested for density, water absorption, compressive strength, tensile strength and erosion resistance. It was found that the pozzolana content slightly improved the blocks’ density. There was increase water absorption resistance of the stabilized blocks between 32.8% and 252% over the unstabilised blocks. The 30% pozzolana content block specimens gained 116.8% compressive strength and 62.1% tensile strength over the unstabilised blocks. Furthermore, there was a statistically signifcant difference in the erosion resistance between the stabilized blocks and the unstabilised blocks. The study concludes that the inclusion of the clay pozzolana generally improved the properties of the CEBs, and therefore recommended it for use in the building of low-rise houses. *Corresponding author: Danso H, Department of Construction and Wood Technology, University of Education Winneba, Kumasi, Ghana Tel: +233 244592831; E-mail: hdanso@uew.edu.gh /dansohumphrey@yahoo.co.uk Received October 01, 2018; Accepted March 05, 2019; Published March 17, 2019 Citation: Danso H, Adu S (2019) Characterization of Compressed Earth Blocks Stabilized with Clay Pozzolana. J Civil Environ Eng 9: 331. Copyright: © 2019 Danso H, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Keywords: Clay pozzolana; Compressed Earth Blocks (CEBs); Compressive strength; Erosion test; Splitting tensile strength Introduction and its activities are also vital to the achievement of the socio-economic development goals of providing shelter, infrastructure and employment [1]. However, the cost of renting or buying a house in developing countries is relatively high to the ordinary citizens due to the high cost of building materials among other factors. Terefore, most people in low-income communities in developing countries wish to become house owners and get at least a suitable accommodation has become an illusion. Te most popular and common walling unit used in most developing countries is sandcrete block, and its essential constituent is cement. Te problem with the cement production is mainly the importation of clinker and gypsum which requires a huge foreign exchange. Tis is coupled with high infation and interest rate, which afect the price built up of cement in most developing countries [2]. Te use of earth blocks as walling units is common in most rural parts of Ghana. In recent past, the collapse of buildings as a result poor nature of earth blocks used has been dramatic in developing countries [3]. Some buildings in some cities of Ghana, especially, Accra and Kumasi have seen the collapse of one form or the other [4] which could be attributed to many factors including the materials used. Researchers have now focused on the type of materials used, and how to introduce additives such as fbres and chemicals to strengthen the building units [2,5]. To this efect, the Building and Road Research Institute (BRRI) of the Council for Scientifc and Industrial Research (CSIR) of Ghana has developed clay pozzolana. Studies on the use of the clay pozzolana have concentrated on concrete and mortar mixes [6-10]. Terefore, there is limited information on the use of clay pozzolana in soil matrix such as compressed earth blocks to enhance its properties for use as walling units. Lack of knowledge on the use earth blocks stabilised with clay pozzolana coupled with the correct quantity of clay pozzolana in the blocks has necessitated for this study. Tis study, therefore, investigates the properties of compressed earth blocks stabilised with clay pozzolana. Te aim of this study is to improve the quality of compressed earth blocks to be used to construct decent but afordable houses. Te objectives of the study are: to determine the physical properties of compressed earth blocks enhanced with clay pozzolana; to determine the mechanical properties of compressed earth blocks enhanced with clay pozzolana; and to determine the durability (erosion) properties of compressed earth block stabilised with clay pozzolana. Te use of pozzolana either as a partial replacement of ordinary Portland cement or with lime has gained widespread popularity in construction. Pozzolan can be defned as a siliceous or alumino- siliceous material with very fne particles, and in the presence of water, it reacts with calcium hydroxide released by the hydration of Portland cement at ordinary temperatures, to form compounds of possessing cementing properties [11]. Pozzolana in the context of concrete technology is actually acidic oxides that will react with the excess basic calcium hydroxide formed during hydration of cement and form ‘neutral’ hydrates [12]. Pozzolana is sometimes preferably used for the construction of structures because of their resistance to the alkali-aggregation reaction, improved durability properties which are due to resistance to sulphate attack [13]. Relatively low-cost materials with cementitious properties are natural pozzolana such as volcanic tuf, clay and waste products from industrial plants such as slag, fy ash and silica fume [14]. Till recently, the use of pozzolana all over the world was as an additive or admixture to cement binders, mainly in mass concrete work, like dam constructions [15]. To reduce the consumption and dependency on cement, utilization of pozzolanic materials as supplementary cementing materials has become the leading research interest in the area of cement and materials research in recent decades [16]. Recently, as a supplement of cement, the utilization of pozzolanic materials in cement and concrete manufacturing has increased signifcantly [16]. Pozzolana is therefore important replacement of cement in recent time due to its sustainable properties. Construction industry plays a major role in most economies