STUDY OF THE INFLUENCE OF TEMPERATURE ON THE INDIRECT TENSILE STRENGTH OF LIMESTONE AT TEMPERATURES OF 25 ?C TO 400 ?C

• Main Author: Prasetya, Heri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80439
• Institution: Institut Teknologi Bandung

One of the problems found in the Underground Coal Gasification process is coal interburden or overburden which is influenced by the increase in temperature in the UCG process. The result of increasing temperature is the formation of cracks in the rock which can affect the stability of the UCG hole, increasing the effects of ground surface subsidence, and the risk of pollutants moving from the UCG process through the cracks into the aquifer. In this research, the effect of heat on the interburden rock or overburden of limestone at temperatures of 25 ? C to 400 ? C has been studied, especially on tensile strength properties which are correlated with physical parameters, ultrasonic speed, cohesion, internal shear angle, and corner toughness properties. and broken (KIc). Compared to testing at room temperature (25 ? C) with testing at 400 ? C, the results showed a decrease in density of 1.26%, porosity increased by 174.29%, void ratio increased by 87.35%, and vp decreased by 17 .59%. In terms of tensile strength, the tensile strength value tends to decrease by 54.23% and the KIc value obtained from the indirect tensile strength test decreases by 54.22%. The tensile strength value of rock (?t) and the KIc value have a directly proportional correlation. This shows that the greater the tensile strength of the rock, the more difficult it is for the material to form fracture propagation. Numerical modeling can model the Brazilian test, with failure criteria using ?t = ?3, numerical modeling can model with a difference of <10%. According to the tensile strength failure criterion, crack propagation in the test sample in numerical modeling can already occur at a value of F = 87- 90%. Modeling is reviewed using the Mohr-Coulumb criteria. It was found that the percent of area experiencing failure increased with increasing temperature by around 22-30%.