Corrosion of steel reinforcements in concrete is one of the main causes of early deterioration and reduction of service loads of reinforced concrete (RC) structures. This paper reports the results of an experimental program that was carried out to evaluate the effect of reinforcement corrosion on the flexural performance of RC beams and to investigate the efficiency of externally bonded carbon fiber reinforced polymer (CFRP) sheets to repair the corrosion-damaged RC beams. Seven RC beams with the same cross section and reinforcement details were prepared including the control beam (B0). First tension reinforcements of six RC beams were corroded by using an accelerated impress-current process to obtain corrosion levels of 15% 30% and 50% of weight loss according to Faraday’s law. Then three beams were repaired using CFRP sheets attached to the bottom surface leaving the other three unrepaired. All beams were subjected to the four-point bending load test. The experimental results show that the corrosion specimens demonstrated a significant deterioration on the structural performance and the integrity by decreasing in their ultimate load capacity stiffness and ductility. The deterioration by corrosion of tension reinforcements can be successfully overcome using CFRP sheets as the repair material. The technique can restore the beam strength to its original design strength except specimen B50F2 having severe steel-corrosion damage of 50%. A conservative value of the ultimate bending capacity of the beams with low corrosions (15%-30%) can be predicted by using RC conventional models as suggested in ACI 318. However the opposite trend is obtained for the high corrosion beam (50%). Appling ACI 440.2R provision to predict the ultimate flexural capacity of corroded beams repaired with CFRP sheets shows rather fair values for low corrosions (15%-30%) but significantly overestimates the strength of the high corrosion beam (50%).

Deterioration of reinforced concrete deep beam structure caused by chloride is severe andtakes up wide area even though the structure is not exposed to sea water or brackish water. Even the structure which is far from sea water or brackish water is affected by this problem.When the reinforced concreate deep beam structure is affected by chloride steel reinforced inside the structure is corroded resulting in reducing the cross-sectional area of the reinforced steel affecting load capacity deflection and beam failure. If there is no repair or strengthening such capabilities are continuously reduced until it is no longer safe to use the beam. Therefore it is necessary to repair or strengthening the deteriorated structure to be safely used. This research investigated strengthening of deteriorated reinforced concrete deep beam caused by chloride with 4 formats of carbon Fiber sheets to seek guidelines for the most efficient strengthening. The resultshowed that the strengthening by the 4 format of carbon fiber sheet could increase ultimate loadcapability yet could not improve ductility of the deteriorated beam to become close to the beamthat is not deteriorated. The strengthening that could increase the maximum ultimate load capability was the table format strengthening. In addition the strengthening that the carbon fiber making 45 degrees with the length of the beam could best prevent diagonal cracks.

This research aimed to develop compound of prototypes polymer bio-composites from cassava starch (CS) reinforced with agriculture residue the rind of durian fruit. Cellulose extracted from durian rind using hot sodium hydroxide and bleaching treatment with hydrogen peroxide. The removal of lignin and hemicellulose components from durian rind were investigated by fourier transform infrared spectroscopy (FT-IR). Cassava starch bio-composite films were prepared by solution-casting technique which includes 0-50 wt% of durian rind (DR) or durian rind cellulose (DRC) as reinforcement agent and urea/glycerol (GU ratio = 50:50) as plasticizer. The physical and chemical properties of thermoplastic starch (TPS)/DR and TPS/DRC bio-composite films were investigated. The percent elongation at break of bio-composite films were increased when compared to control CS film. From 15TPS/DR (80/20) films showed increase the elongation at break from 7.28 to 14.00% when compared to CS control films. While 15TPS/DRC (80/20) bio-composite films exhibited that the highest elongation at break to 77%. Durian fiber (DR or DRC) loading decreased the water absorption of plasticized bio-composite films. Furthermore incorporation of DRC in composite can be enhanced film stability in water better than DR. Therefore the effect of DRC reinforcement agent on TPS bio-composite films can improve water resistance and mechanical properties especially in terms of flexibility. Finally the waste of bio-composite films was degraded completely in soil burial test.

This research project has developed and produced natural fiber-reinforced cement tiles by incorporating natural fibers from para rubber leaves and torpedo grass and mixing them with cement and then compressed into a mold with dimensions of cube was 5 cm x 5 cm x 5 cm. The ratio of fiber and cement were 1:9 2:8 and 3:7 respectively. This study used both types of natural fibers including para rubber leaves and torpedo grass. This research found that torpedo grass mixed with cement in a ratio of 1:9 provided high quality of reinforced cement. The density of this sample was found 2.07 g/cm3. Moreover the dry shrinkage value and water absorption were 0.02% 0.10% respectively. The compressive strength was 64.25 kN or 0.23 MPa. In comparison with the standards of non-load bearing concrete blocks according to TIS 58-2530 the result shown that some experimental data are lower than criteria standard. Furthermore the adhesives (i.e. silica) are very important for the quality of natural fiber-reinforced cement

This research aims to study the properties of natural rubber STR 20 at 100 phr with various contents of coir (e.g. 0 5 10 20 40 and 80 phr) and then mixed with chemical substance at constant ratio. After that the samples are ground by two-roll mill and formed by compression molding at 150 degree Celsius. This leads into the coir reinforcement natural rubber plate of dimension 30x30x0.5 cm. The properties of the natural rubber plates are tested under ASTM standard. From the results it is found that increasing in coir then the properties of resilience and density are improved at every mix ratio. However the tensile strength tear strength and wearing are increased at some certain value of coir. The samples give no water absorption at every mix ratio. The results from this research indicate that it can develop into the rubber floor tiles and rubber wall tiles for furnishing the buildings in natural style.