PRODUCTION AND EVALUATION OF CONCRETE HOLLOW BLOCKS WITH CRUSHED POLYETHYLENE TEREPHTHALATE (PET) AS ADDITIVES

     Waste pollution is one of the major problems that the world is facing today. One of the waste that is very abundant is Polyethylene Terephthalate (PET) bottles which are used as food packaging.

     The purpose of the study was to evaluate the potential of the crushed Polyethylene Terephthalate (PET) bottles as additives of concrete hollow blocks. Using One-way Completely Randomized Design the results were analyzed and compared using the least significant difference. This study was conducted from February 18, 2017 to April 12, 2017 at Agricultural Engineering Complex, Mindanao State University, Brgy. Fatima, General Santos City.

     There were 4 treatments used in the study. Treatment 1 has 10% addition of crushed PET, while treatments 2, and 3 have 20% and 30% addition respectively. Treatment 4 is the control with no addition. The concrete hollow blocks were subjected to compression test, water absorption test, thermal conductivity test, and specific gravity test. The result showed that the Treatment 2 has the highest compressive strength with mean of 3,205.86 kN/m2 though not significantly different to the Treatment 4. Water absorption of Treatment 2 has the lowest value of 8.64% and it is significantly different to the other treatments. Treatment 3 has the lowest thermal conductivity among all treatments with 1.50 W/K-m. It is significantly lower compared to other treatments. The specific gravity of treatment 3 is also the lowest 1.80 but there is no significant difference among treatments. The addition of the PET has increased the volume of concrete hollow blocks produced and lowered the cost per CHB.

     It is recommended that the testing material for the addition of PET should be considered as an insulating material instead of construction material. The crushed PET bottle used should be finer form. Also, the concrete hollow blocks should be formed by the manufacturers of concrete material in order to have a uniform application of pressure and more mixing ratio should be used in order to find the best mixing ratio for the CHB.