Environmental Technology & Science Journal (ETSJ) 01/2008; 3:81-87.


Effect of calcium oxide on volcanic ash laterized concrete was investigated. A total of 60 cubes of 150mm dimensions were cast with volcanic ash (V.A) and calcium oxide (CaO) combination of 90%:10% and 80%:20% respectively while the ordinary Portland cement (OPC) based concrete for 28-day target strength of 25N/mm2 served as control. Sand replacement by laterite also varied between 0% and 20% for the laterized specimens. The cubes were cured in water and tested for compressive strength at 7, 14, 21 and 28 days. The result showed that the compressive strength increased as the hydration period increased and that the presence of calcium oxide boosted the strength properties of volcanic ash laterized concrete. The compressive strength of the laterized concrete specimens was higher at the various hydration days for the 20%lat/20%CaO: 80%V.A. sample than the 10%lat/10%CaO: 90%V.A sample. The 28-day strength for 20%lat/20%CaO: 80%V.A sample gave a value of 22.07N/mm2 (i.e. 81.74%) as against the 21.53N/mm2 (79.74%) gotten for the 10%lat/10%CaO: 90%V.A. sample, while the control mix gave a 28-day strength value of 27.0N/mm2 (100%). The volcanic ash – lime cement in the laterized concrete specimens therefore reflects good pozzolanic activity and can be adopted for construction of buildings and rural infrastructure.

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Available from: Ezekiel Babatunde Ogunbode
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    • "So also are low-cost housing schemes in some States like Kebbi, Ekiti and others in Nigeria built with hydra-form (i.e. interlocking stabilized laterite) blocks[3]. However, it has not been widely utilized to an equal level as sandcrete blocks and concrete, especially for structural works[23]. "

    Full-text · Article · Sep 2012
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    • "Due to this reality, an alternative source for the potential replacement of fine aggregates in concrete has gained good attention. As a result, reasonable studies have been conducted to find the suitability of laterite replacement for sand in conventional concrete and the use of waste ash to replace cement [1] [2] [3] [4] [5] [6] [7]. The high cost of building materials in Nigeria has made inexpensive housing out of reach of the average national of the country. "
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    ABSTRACT: This paper discusses the experimental results of tests carried out on the Strength properties of Laterized concrete (LATCON) made with Cassava peels ash (CPA) an agricultural waste at varying levels of replacement to Ordinary Portland cement (OPC) up to 40%. The Strength properties, namely compressive strength, initial surface absorption and Density were measured in the laboratory on 375 100x100x100mm cube specimens with the view of establishing the percentage of the ash and laterite that can be used in the cement matrix and fine aggregate compositions respectively. The best strength performance was obtained at 30% of cement replacement while the laterite (lat.) will perform better at 30% fine aggregate replacement for concrete production which was comparable to normal concretes (i.e. Control). It is therefore concluded that the CPA/OPC LATCON has sufficient strength and adequate density to be accepted as structural concrete.
    Full-text · Article · May 2012
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    ABSTRACT: In this work, the effect of addition of Calcium Nitrate on selected properties of concrete containing Volcanic ash as partial replacement for ordinary Portland cement by weight was investigated .The study carried out used 10% volcanic ash as partial replacement and an admixture, Ca(NO3)2 Was added to improve the strength of the resulting concrete at 2%, 4%, 6% 8% and 10% respectively. The result of setting time showed a decrease in both initial and final setting time of the mixture as the Ca(NO3)2 Content was increased. The result of chemical analysis of volcanic ash showed an increase in calcium oxide (CaO) content when calcium Nitrate Ca(NO3)2 was added from 11.67% to 33.68%. Cubes were cast and cured in water for 7, 14, 21, and 28 days .The resulting Strength at 28 days hydration period shows a strength increase as the percentage of Ca(NO3)2 was increased to 10% .
    Full-text · Article · Dec 2011 · Leonardo Electronic Journal of Practices and Technologies
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