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Concrete has a high compressive strength, but it is low to tensile strength. The pinang skin fiber and wood powderuse to increase the tensile strength. The purpose of this research is to know the effect of addition toward tensile strength and addition percentage variation in concrete that will get the highest tensile strength.The cylindrical specimens with size of 30 cm high and 15 cm diameter to 20 specimens, they are 4 sample of normal concrete and 16 sample of variation oncrete. The addition of pinang skin fiber and wood powder with variation of 0.25%, 0.5%, 0.75%, and 1% of the weight volume of the specimen with used 50% pinang skin fiber and 50% wood powder.The mixture of concrete uses water cement ratioof 0.5 and 60-100 mm slump.The test specimen is immersed for 26 days and the concrete tensile strength test conducted after the concrete at 28 days adding 7 days for drying.The result of this research shows that the variation concrete of 0.25% and 0.5% have increased of tensile strength than the normal concrete as 12.272% and 4.369%. Beside that for the variation concrete of 0.75% and 1% have decreased as 5.044% and 11.929%. The increase of tensile strength value of optimal concrete is found in variation 0.25% that is 12.272% from normal concrete.

Mortar is a mixture of adhesives (portland and lime cement), sand and water with certain compositions. Use of adhesive materials on building construction in general still use portland cement, but in terms of portland cement costs are required a greater cost. This study aims to determine the behavior of the compressive strength of mortar using Coconut Shell Charcoal (CCS) as a substitute for cement. The method of manufacture and testing of mortar compressive strength refers to SNI 03-6825-2002 with mortar 1Pc: 3Ps mortar. Range of initial flow values used is 105% - 115%. CCS used is pass No. 200 which utilizes combustion results from coconut shells. Variations of mortar test specimens were 0%, 2.5%, 5%, 7.5%, 10% and 12.5% respectively each variation had 10 sample specimens. Test sample was immersed for 27 days and compressive strength mortar test was performed at 28 days. Value compressive strength of mortar on variations of 0%, 2.5%, 5%, 7.5%, 10%, 12.5% are 25.11 MPa, 25.65 MPa, 26.07 MPa,27.00 MPa, 26.40 MPa and 25.98 MPa. The highest increase of mortar compressive value was variation of 7.5% by 7.51%.

This research was motivated by the contained SiO2 in zeolite. The purpose of this research was to know the zeolite effect as a substitute of cement in constructing 14 days paving block material which used conventional method toward the compressive strength of paving block. This research used SNI 03-06-1996 in constructing and testing the materials. The material was cube shaped with ±5 cm size which consists of normal paving block and 6 variations with 5 specimens of each variation. Total of specimen were 35. Substitute of zeolite variations used 2,5%, 5%, 7,5%, 10%, 12,5%, and 15% on the weight of cement. The result of compressive strength of normal paving block is 15,64 MPa. The result of compressive strength test had increased in the variation of 2,5% zeolite substitute by 6,28% normal paving block. The result of compressive strength test results showed the greatest decrease in variation of 15% zeolite replacement by 39,05% against normal paving block.