The research aims to investigate the possibilities of crushed oyster shell (OS) not have to go through the process of burning as a substitution cement for concrete blocks. The cement was replaced with crushed oyster shell not process burning (OS) at 0% 10203040 and 50% by the weight of the binder. After that the concrete blocks were tested to determine the compressive strength and moisture absorbed of the concrete blocks cured for 7 142856 and 90 days The result showed that the compressive strength of the concrete blocks which replaced cement with OS (at the proportion of 10% by the weight of the binder) at 28 days had the compressive strength and water absorbed accordance with the TIS 58-2533 on non-load bearing concrete blocks.Moreover the concrete blocks which replaced cement with OS at the proportion of 20 % and 30 % had the compressive strength equivalent to 28 days compressive strength of TIS 58-2533 standard at 56 and 90 days respectively and decreased when the percentage in addition to OS in concrete blocks of 40 and 50 %. Tested results also showed that the water absorbed of concrete blocks increased when the percentage of replacement of OS in binder increased at 10 20 30 40 and 50%. The economical of concrete blocks it has manufactured unit cost is 2.60 baht. Whereas the concrete block containing crushed oyster shell at 10-30% it has manufactured unit cost at 2.12-2.44 baht respectively.

The study aims to study the change leadership that affects the organizational culture and work efficiency of the staffs at the operational level and to study the good governance principles that affect the organizational culture and work efficiency of operational staffs at Commercial Concrete Production Business Unit. The population used in the study is 200 operating staffs at Commercial Concrete Production Business Unit using questionnaires for data collection. The data analysis is conducted using descriptive statistics and inferential statistics. The result indicates that change leadership affects organizational culture of operational staffs with statistical significance at 0.05 level. It can predict the organizational culture of operational staffs at 16.30 percent. Good governance principles affect the organizational culture of operational staffs with statistical significance at the level of 0.05. It can predict the organizational culture of operational staffs at 29.50 percent. Change leadership affects the operation efficiency of operational staffs with statistical significance at the level of 0.05. It can predict the work efficiency of operational staffs at 13.80 percent and good governance principles affect the work efficiency of operational staffs with statistical significance at the level of 0.05. It can predict the work efficiency of operational staffs at 28.70 percent.

This paper present the engineering properties of asphalt (AC 60/70) modified with different ratios of crumb rubber. Then select the best properties of the binder to mix asphaltic concrete. From laboratory testing results with adding 11% crumb rubber into mixtures for the best results. The properties of asphaltic concrete can be improved by adding 11% crumb rubber. For asphaltic concrete Marshall Stability increased and flow decreased with adding crumb rubber into asphalt. Comparing to ordinary asphaltic concrete (AC 60/70) the rutting resistance was increased 18% for crumb rubber modified asphalt respectively. Moreover the fatigue resistance of crumb rubber modified asphalt improved to be 1.59 times compared to AC 60/70.

This paper present the engineering properties of asphalt (AC 60/70) modified with different ratios of natural rubber. Then select the best properties of the binder to mix asphaltic concrete. From laboratory testing results with adding 6% natural rubber into mixtures for the best results. The properties of asphaltic concrete can be improved by adding 6% natural rubber. For asphaltic concrete Marshall Stability increased and flow decreased with adding natural rubber into asphalt. Comparing to ordinary asphaltic concrete (AC 60/70) the rutting resistance was increased 22% for natural rubber modified asphalt respectively. Moreover the fatigue resistance of natural rubber modified asphalt improved to be 2.06 times compared to AC 60/70.

This research to study the possibility of material pozzolan as binder by replacment cement by fly ash (FA) and meta kaolin (MK) some for testing compressive strength flexural strength and impact strength of concrete vary the ratio of water to binder (w / b) of 0.40 and 0.45 and the amount of fly ash to replace cement some 15 % 30 % MK and 35% for 10% 15% and 20% by weight of cement. The sample consisted of a cylinder diameter of 10 x 20 cm beam sizes 10 x 10 x 40 cm and 4 x 4 x 16 cm from the test results showed that the concrete samples at 28 days and w/ b of 0.40 to greater than 0.45 all mixed. the compressive strength by replacing cement with FA increase up to 30 % compression of 382 ksc higher than the 20 percent replace by MK were equal to 354 ksc and 32.48 ksc compared to replace cement with FA 15 % is equal to 31 ksc 30% were equal to 30 ksc and 45% were equal to 23.85 ksc while the MK was replaced by 10% were equal to 40.10 ksc higher than to 15% and 20% respectively. The control sample was replaced with MK by 10% is equal to 111 joules maximum replaced by fly ash more than 30% were equal to 110 joules and MK were 15% fly ash 15 and 45 percent respectively.