Physical Disintegration of Mudrock Samples in Hambalang Area, Bogor, Indoesia
Misbahudin MISBAHUDIN#+
Universitas Pertamina, Indonesia

Many of the infrastructure buildings are built on a foundation from sources of mudrock. Hambalang, Bogor, Indonesia is an area that has projected infrastructure buildings, including national sports facilities and housing for residents. Previous reports have stated that construction problems mainly originate from unstable foundation material due to the presence of mudrock and its weathering product. Mudrock can be evaluated for its disintegration characteristics through immersion and drying which minimizes mechanical forces. The research was conducted by testing the physical disintegration of several mudrock samples from Hambalang, to later become an engineering consideration in ongoing or future infrastructure activities. The test is mainly the preparation of rock samples weighing 450-550 grams which are dried in sun exposure for two days. The samples were then immersed in a water-filled beaker for 24 hours. Series of tests for the physical properties of rocks were also carried out to obtain water content, dry density, porosity, and absorption.Based on the disintegration index value that has been obtained, the quantitative approach shows that all samples have a high index. This indicates low disintegration characteristics. This is different when observed physically through immersion tests. The intact sample has mostly deteriorated into angular fragments that show clear evidence of the disintegration of the rock. Further review is needed regarding the characterization of mudrock disintegration in Hambalang. Field observations with visual during immersion observations show similar conditions in the form of disintegrated rocks.