HomePULSARvol. 2 no. 1 (2013)

Compressive Strengths of Concrete Hollow Blocks Using Rice Husk Ash

Eugene V. Laruan | Reymund B. Bonares | Moam-mar K. Abdulkasan | Ruben M. Ruiz

Discipline: Engineering, Applied Sciences



Substituting waste materials in construction is well known for conservation of dwindling resources and preventing environmental and ecological damages caused by quarrying and depletion of raw materials. Many researches had shown that some of these wastes have good pozzolanic properties that would improve the quality of concrete hollow blocks produced. One such waste material is agricultural waste rice husk. Concrete hollow block is absolutely part of the construction industry. However, the paces in development lead to increase in demand for the basic construction materials like cement. The increasing demand of cement which is used as a primary binder in making of concrete hollow blocks leads to the increased cost of these materials and has posed a problem to the growing needs of some builders in the country today. This predicament leads the researcher to look for possible partial replacement of cement by investigating the potential use of rice husk ash as replacement for cement in making concrete hollow blocks. This study sought to answer the following research question. What are the compressive strengths of concrete hollow blocks using the conventional, 80% Ordinary Portland cement-20% Rice husk ash, and 60% Ordinary Portland cement-40% Rice husk ash mixtures? Likewise, these mixtures as components of hollow blocks were tested to determine whether they significantly vary in terms of compressive strength of the produced blocks. The researchers investigated the possibility of using rice husk ash in reducing the amount of cement in making concrete hollow blocks. The mixtures classified as a standard 1:8 mix proportion, one part of cement to eight parts of sand in a different mixtures of Ordinary Portland Cement and Rice Husk Ash. Three sets of mixture with fifteen samples for each were made for a grand total of 45 samples. All was cured in fourteen days and were tested after 34 days. Findings of the study revealed that as the percentage of rice husk ash in the mix was increased, the compressive strength of concrete hollow blocks decreased. Furthermore, concrete hollow blocks containing 40% rice husk ash were not good enough to be used as load or non-load bearing partition concrete hollow blocks but blocks containing 20% rice husk ash were suitable for use as non-load bearing partition. Thus, concrete hollow blocks containing 20 percent rice husk ash only could be used for non-load bearing partitions, other than fire walls