Abstract: This research observed the concrete strength, which made using mixture composition with and without mix design analysis. Mixture base on mix design is measured base on weight comparison, and mixture without mix design analysis is measured base on volume comparison between cement, sand, crushed stones / aggregate, then the mixing process done in the field (Site mix). The fine aggregate used is the fine grain sand (gradation of zone 3). Mix design analysis used DOE method. The quality of plan concrete fc′ is 20 MPa and 25 MPa. Comparison of volume of cement: sand,: crushed stones to the plan quality concrete fc′ 20 MPa and 25 MPa, respectively is 1: 2: 3 and 1: 2: 3.5. To know the development of concrete strength, it is done pressure strength test at age 7, 14, and 28 days. Else, also is done porosity test to the concrete at age 28 days. From testing result of concrete pressure strength at age 28 days was found value of pressure strength in all concrete test objects fulfilled plan pressure strength, either mix design concrete or volume comparison. The fine gradation grain sand (zone 3) was not reducing the concrete strength planned. Concrete pressure strength value based on volume comparison was higher than mix design concrete. The result of porosity test pointed out percentage rate of concrete cavity based on volume comparison was lower than mix design concrete.

Keywords: concrete, mix design, volume comparison, concrete strength, smooth grain sand

Penulis: Iskandar BP

Artikel ini telah dipublikasikan pada Journal of Basic Sciences and Applied Research (JBSAR). Basic Appl. Sci. Res. Volume 6 No. 3 Maret 2016. Hal: 38-43.

Artikel ini juga telah direview oleh reviewer internal Universitas Muslim Indonesia (UMI) Makassar. Berikut hasil review dari reviewer internal: