This research presents the engineering properties of asphalt (AC 60/70) modified with different ratios of scrap natural rubber. Then select the best properties of the binder to mix asphaltic concrete. From laboratory testing results with adding 7% scrap natural rubber into mixtures for the best results. The properties of asphaltic concrete can be improved by adding 7% scrap natural rubber. For asphaltic concrete Marshall Stability increased with adding scrap natural rubber into asphalt. Moreover the stiffness modulus of asphaltic concrete can be improved 13.53 compared to AC 60/70.

The purpose of this research is to study the effect of safety measure to construction productivity for ceiling activity by studying a construction of buildings in Bangkok. The safety system composed of (1) stable scaffolding system (2) providing clean and not slip walkways on the scaffold (3) installation of handrails not less than 0.90 meters in height (4) installing stairs (5) providing personal protective equipment for workers (6) are responsible for scaffolding and (7) scaffolding permit document. Cost of the safety system is 23908 baht or approximately 33 baht/m2. Productivity rates for prior and after the used of safety system are 1.57 and 1.41 m2. /person/hr. respectively. The productivity declines for approximately 10.19 % the working time for ceiling could take longer for 10.45 % and labor cost could increase for 10.19 %.

This research aims to study how to use stones Pumice Products is interlocking block for community development. The mixture ratios of Portland cement type1: sand: quarry dust: pumice rock fragments: water that there are 5 ratios. The products were tested by the community TCPS 602-2547 (2004) (Thai): interlocking block. The results showed that interlocking block of stone pumice much a compressive strength and thermal conductivity under a block of stone pumice less. The water absorption is increased When a block of stone pumice much. The optimum ratio and the use of waste rock Pumice highest ratio of cement to stone dust on the stone Pumice water in a 10: 6.4: 0.6: 0.45 to 10: 6.1: 0.9. 0.45 by weight.

The objectives of this research are to study the production step proper ratio physical properties mechanical properties thermal insulation and sound insulation efficiency of concrete blocks mixed with coconut shell ash. The ratios of concrete block mixed with coconut shell ash include Portland cement type1: quarry dust: coconut shellash which equal to 1: 6.8: 0.2 1: 6.7: 0.3 1: 6.6: 0.4 1: 6.5: 0.5 and 1: 6.4: 0.6 by weight. Water per cement ratio are 0.6 by weight. The concrete block samples were casted by the general production as same as the ordinary concrete blocks and were tested follow TIS.58. From the results the best amount of coconut shell ash which put into concrete block is 1: 6.7: 0.3 of ratio. The proper ratios of coconut shell ash can decrease the density or weight and increase the thermal insulation and sound insulation efficiency of concrete blocks. However the high amounts of coconut shell ash effect to decrease the mechanical properties concrete blocks that are lower than TIS.58 standard.

The purpose of this research is to study the effect of a safety system provided for column reinforcement activity on productivity by studying a construction of buildings in Bangkok. The safety system composed of (1) stable scaffolding system (2) providing clean and not slip walkways on the scaffold (3) installation of handrails not less than 0.90 meters in height (4) installing stairs and (5) providing personal protective equipment for workers. Cost of the safety system is 40030 baht for a column reinforcement area of 40 numbers. Productivity rates for prior and after the used of safety system are 11.06 and 8.80 kg./person/hr. respectively. The productivity declines for approximately 20.43 % the working time for column reinforcement could take longer for 13.18 % and labor cost could increase for 13.32 %.