Concreting Workmanship in Indonesia Study Case: Padang City, West Sumatra, Indonesia

Abstract

This research gives information about the practice of concreting work in Reinforced Concrete (RC) building project in Indonesia. The study area is Padang City, which has suffered severe damages due to September 2009 Earthquake. The target interviewee is 100 builders who are constructing RC buildings. This interview together with observation was conducted by directly visiting the construction sites. While collecting information about the main factors which contribute to RC building quality, e.g., concrete mixing, compaction, concrete placing and curing, the information about the profile of the builders have been collected.  The results show that the workers dominate the profile of builders in productive age with 30 years experiences on average. However, 90% of the builders yet experience any construction workshop. The concreting work, which is conducted by the builders, yet reaches the required standard. More than 50% of the builders produced concrete with the higher water-cement ratio, and almost 65% admitted that they add more water after concrete`s setting time is finished. There are 3common methods of concrete compaction which is used.  6% of the builders use a vibrator, 43% use the rodding method, 28% use hummer, and 8% choose to add more water to placed concrete to increase concrete workability. Meanwhile, more than 60% of the builders do not cure the placed concrete. The results show that construction practice that is conducted by the local builders is needed to be improved. The mistakes seem to be repeated over a generation since the source of learning of the builders is mainly from their senior builder (77.25%) and self-learning (2.5%). Only 7.5% that admitted they had experienced on construction workshop.