Mortarless concrete hollow blocks with rice straw ash / Rhei Angelo C. Aguila [and 4 others].

Undergraduate Theses (BSCE) - Civil Engineering. Camarines Sur Polytechnic Colleges, 2022.

Includes bibliographical references.

This study is about developing mortarless concrete hollow blocks (CHB) mixed with rice straw ash (RSA). The researchers tested whether there is a significant difference between the properties of plain mortarless concrete hollow blocks and mortarless concrete hollow blocks mixed with rice straw ash in terms of density, moisture content, water absorption, and compressive strength. Several tests were conducted to check the difference between the two variables, such as a moisture content test, an absorption test, and a compressive strength test. The results from the above-stated tests showed that there is only an acceptable trial mix proportion from the control group (CHB without RSA) that can be considered to achieve the standard compressive strength. The compressive strength of the CHB with RSA decreases if the percentage of partial replacement of RSA increases. The greater the RSA replacement for cement, the more water it contains; however, the greater the RSA replacement for cement, the less water it can absorb. The tests also revealed that there is a significant difference between the compressive strength of plain mortarless concrete hollow blocks and mortarless concrete hollow blocks with rice straw ash for trial mix B and C since the computed t-value are greater than the critical t — value, rejecting the null hypothesis.