TINJAUAN KUAT TEKAN BEBAS TANAH LEMPUNG YANG DIPERKUAT DENGAN SERAT SABUT KELAPA

Clay is a soil mineral with a particle size of 0.002 mm, resulting from the rock weathering process. Clay is soil with unfavorable conditions if it is used in building construction, an example of a clay that is not good enough to be used as the subgrade of a building is soft clay, because soft clay has a high plasticity and shrinkage value. Coir fiber is an organic fiber as a part of coconut which has a high tensile strength value and has stress resistance. Coir fiber can make clay soil stability better when mixed with a certain amount. This study aims to assess the stability of the reinforced clay using coir fiber with a fiber length of 6-8 cm. The test carried out is the unconfined compressive strength based on SNI 3638-2012. The specimens have a diameter of 3.5 cm and a height of 7 cm. The specimens were mixed with coir fiber's percentage as much as 0.00%, 0.25%, 0.50%, 0.75%, and 1.00% of the total weight of the mixture. The test results show the value of the compressive strength of clay without coir fiber is 72.10 kPa. After being mixed with coir fiber, the strength value increased with increasing fiber percentage, and the optimum unconfined compressive strength value occurred at 0.75% fiber blending with a strength of 153.26 kPa. At the time of mixing coir fiber with a percentage of 1.00%, the value of the unconfined compressive strength decreased to 73.50 kPa. The maximum secant modulus value was obtained when mixing clay with the coir fiber's percentage as much as 0.50% with a value of 49.43 kPa