Pengaruh Kuantitas Perojokan Dan Paparan Lingkungan Terhadap Mutu Benda Uji Beton Silinder

Abstract

Concrete is a composite material for it is consisted of some other materials, being mixed until homogen and monolith. But, however the mixture diversification or certain compaction method are being done, there is chance of bubbles or air pores occurance who degrade the design strength. Furthermore, concrete curing holds an important role for preventing the rush of initial cracks. The emerging of initial cracks follow concrete's volume-shrinkage, which is led by fast evaporation and the hydration process. This study observed concrete's compression strength, represented by six type of mashing-quantity, 0, 5, 10, 15, 20, 25 times of mashing per layer. Each type is represented by two samples. Samples made are cylindrical with 150 mm in diameter and 300 mm in length. Material specification is conventional industrial concrete K-250 with 120 mm slump. Samples were made by single mixing in Indonesia's average weather and temperature. After being molded, samples were stored in environmental ambiance (exposed by direct sun-ray, wind, etc.). From the experimental research, we're achieving the optimum compression strength of 20 times mashing per layer-sample, 15,09 MPa. The exposure of environmental ambiance reduces 30% of concrete's design strength. Kata kunci: kuat tekan, benda uji silinder, jumlah rojokan, paparan lingkungan.