doi:10.3850/978-981-08-7920-4_S4-H02-cd

ABSTRACT

Cement being the main component of construction activity, construction industry is considered to be the major contributor of Green House Gas emissions. New cost effective and energy efficient technologies for housing are, therefore, a need of the hour. Development of Soil-Cement- Fly ash (SCF) blocks for cost effective and energy efficient housing presented in this paper is one such attempt. The paper describes the investigation carried out to study the strength and durability of SCF blocks besides making it carbon neutral. Locally available soil is blended with 5% cement and fly ash varying from 5 to 50% with increments of 5%. Blending of soil with fly ash was done to achieve the grading of blended soil which closely matches the Fuller curve of minimum voids. Optimum fly ash content to be added in the mix was determined from experimental programme and standard SCF block specimens of size 215 × 100 × 75mm were prepared and cured. The SCF blocks were then subjected to compressive strength test and durability test. The discussions presented in the paper indicate wet compressive strength in the range of 3.3MPa to 5.3MPa and dry compressive strength in the range of 3.7MPa to 8.2MPa. Further, ratio of wet to dry compressive strength was found to be varying from 0.49 to 0.90. The loss in weight of SCF blocks on twelve cycles of wetting and drying was observed to be far below the permissible value of two percent. There is significant increase in impermeability of the block due to addition of fly ash. The paper further highlights the significant increase in the ratio of wet to dry strength of SCF blocks, and reduction in loss of their weight on wetting and drying test with increase in fly ash content, thus reflecting the improved durability of blocks. This may be attributed to addition of fly ash which fills in micro pores and proper grading of blended soil resulting in increased density followed by strength and durability. The paper also presents the study carried out on energy values of SCF blocks. The study reveal that SCF blocks so developed are carbon neutralwith the energy value of -0.036MJ per brick with 10% addition of fly ash, whereas the energy content of burnt clay brick is 4.35 MJ per brick. The research work presented in this paper foresees high potential and bright future for SCF blocks for development of sustainable and cost effective housing for human beings.

Keywords: SCF block, Fly ash, Embodied energy, GHG emissions, Carbon neutral.

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