MIXTURING OF LUMAJANG?S SAND AND BANGKALAN?S GRAVEL FOR 20 MPA QUALITY CONCRETE, REVIEWED FROM QUALITY MANAGEMENT.

Bangkalan Regency has an aggregate that has the potential to use a concrete mixture in the form of sand and gravel. SandBangkalan Regency has an aggregate that has the potential to use a concrete mixture in the form of sand and gravel. Bangkalan sand has a very fine structure, so this material is rarely used as a mixture of concrete because with its fine structure the quality of the resulting concrete will be less good. Repairing gradations or combinations of 10/20 with 5/10 gravel from Bangkalan Regency and the use of sand from Lumajang Regency are expected to reach fc \'20 Mpa quality concrete. This study aims to obtain compressive strength of concrete using Bangkalan gravel mixture and Lumajang sand compared to using Bangkalan gravel in terms of quality management using statistical tests, an average of two and an average of three. The study was carried out in the laboratory, to obtain the compressive strength of a cylinder using a specimen size of 15 cm x 30 cm each variation of 30 specimens for quality concrete fc \'20 Mpa, Variation 1 combination of use of gravel size 5/10 and 10/20 and sand from Bangkalan, variation 2 uses lumajang sand as a substitute for Bangkalan sand. The results of statistical tests using an average test of two and an average of three concrete using sand and gravel from Bangkalan did not meet the satisfactory concrete quality of 26.70 Mpa because the characteristic concrete compressive strength only reached 15.62 Mpa. While concrete using sand from Lumajang and gravel from Bangkalan at 23.79 MPa. However, when viewed from the compressive strength of the concrete characteristics using Lumajang sand and Bangkalan gravel it has reached a quality of 20 Mpa