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Fiber Reinforced Plastics (FRP) has been widely applied in many purposes in civil engineering fields. Especially, FRP sheet is very suitable for strengthening of the existing structures. FRP sheet may be applied in various environment conditions of the structures. Many structures have to resist aggressive environment condition such as sea water exposure. Study on the effect of sea water exposure to the moment capacity of the concrete beams strengthening using GFRP sheet is important regarding to the effectiveness of strengthening. An experimental program has been conducted to find out the relationship of the moment capacity of the RC beams strengthened using FFRP sheet to the time of sea water exposure. A series of experimental specimens were prepared to be exposed in the sea water for 24 months. The beam specimens had the dimension of 3000 mm length with 150 x 200 mm of cross section. The specimens were reinforced by steel bars based on the under reinforced condition. The strengthening of the RC beams was conducted after 28 days of curing. The strengthened specimens were then submerged into sea water. The investigation on the moment capacity was conducted for 6 month, 12 month, 18 month and 24 months of exposure, respectively. Results indicated that the moment capacity of the beams decreased as the increasing of the exposure duration. Based on the experimental data, a relationship model of the effect of sea water exposure duration to the moment capacity was developed. The developed model may be used to predict the effect of sea water exposure to the moment capacity of GFRP sheet strengthened RC beams in design. [ABSTRACT FROM AUTHOR]

For marine applications, composite materials offer many advantages over metallic structures, with respect to ease of fabrication of complex profiles or light weight for installation and maintenance. Nevertheless, material selection is critical. In the case of a composite material, the choice of reinforcement is important if stress corrosion is to be avoided, while resin chemistry must be optimized to limit matrix damage. Fiber/matrix interface properties are also critical when composites are immersed for long periods. The main objective of this study is to identify and quantify the influence of the specific environmental marine conditions on composite material behavior, especially in cyclic loading. In order to perform a comparative study of fatigue behavior, three composite materials have been tested and analyzed. Fatigue tests have been carried out in bending on composite materials at initial state and after sea water ageing. The fatigue life and the evolution of the damage have been compared for each material. These experimental data allow us to identify and compare the fatigue behavior of several composite materials in a marine environment. [ABSTRACT FROM AUTHOR]

Indonesia is the largest archipelago in the world, so it has much territory that the quality of the source water is not qualified as mixing water in construction. Besides, construction of concrete in areas that are likely quantity of water or fresh water is very minimal or even nothing then the sea water cannot be avoided in mixing concrete. This research was an experimental study, the samples for compressive strength test are cylindrical premises size of 10 mm×20 mm. The porosity relation, compressive power, age and model of porosity relationship with SCC concrete compressive strength which using sea water is discussed in this paper. Compressive strength testing is following the standard ASTM 39/C 39-99. Universal Testing Machine (UTM) was used in the testing of compressive strength. Test specimen for porosity created by taking part of the cylinder and then slashed with a size of approximately 2 cm×3 cm with a 0.003 mm thick. The type and pore size and porosity were analyzed by using a polarizing petrography microscope Olympus BX 51-P. The result of research was increased the compressive strength and density of microstructures in line with the decrease in porosity and pore size of concrete and concrete age. Compressive strength relations (σ ss ) and porosity (p ss ) the SCC used sea water can be approximated equation σ ss = σ o (1-p)K, with σ o = 119.6 and K = 7.502. [ABSTRACT FROM AUTHOR]

Structures built in the marine environment need to be carefully designed, due to the possibility of chloride ion penetration into the concrete. Among these attempts, FRP was evaluated as one of the best methods to deal with the problem because FRP does not corrode even in marine environment. This study presents the results of the application of GFRP sheet for strengthening of the concrete beams. A series of specimen of reinforced concrete beams with dimension 15×20×330 cm were cast. The samples were tested under different duration of the immersion of sea water. Beams were immersed in sea water for 1 month (BF 1 ), 3 months (BF 3 ) and 6 months (BF 6 ). Three specimens were prepared control beam without immersion to sea water (BF 0 ). The results indicated that the flexural capacity of BF 1 , BF 3 , and BF 6 when compared to that of BF 0 decreased by 2.65%, 2.73% and 3.78% respectively. The decreasing was caused by the weakening of the bonding capacity GFRP due to the influence of sea water immersion. [ABSTRACT FROM AUTHOR]

The installation for newformed surface creation of the metal has been developed. Experiments were carried out in model solutions of NaCl on samples of various shipbuilding metals. Shipbuilding metal potentials without oxide film in the marine and ocean water have been obtained. The results show how much the steel potential value were critical “inside” the crack under corrosion-mechanical and fatigue destruction. The obtained results show that the electrochemical corrosion account is possible at application of high-tensile steels, which used in dynamically loaded constructions in corrosion environments. Investigation of the steel protection parameters in relation to specific products and service conditions may allow to control the corrosion fatigue properties of metals and predict this characteristics in the future. [ABSTRACT FROM AUTHOR]

Abstract: Water absorption of natural fiber composite is of serious concerned especially for outdoor application. In this study, long kenaf/woven glass hybrid composite is fabricated in-house using cold press technique. The effect of water absorption on the hybrid composites is investigated at room temperature under three different environmental conditions, i.e. distilled water, rain water, and sea water. The moisture absorption amount is obtained by calculating the different percentage weight before and after the immersion process. The moisture content is found to exhibit non-Fickian behaviour regardless of three different conditions. Liquid exposure of long kenaf/woven glass hybrid composite deteriorates the fracture toughness due to the weakening of interface between fiber and matrix. There are also several recognized modes of humidity aging found through SEM observation. [Copyright &y& Elsevier]

Abstract: Today, seawater and brackish water desalination is a subject of concern of many researchers all over the world. The recourse to the desalination by distillation using solar energy represents an appreciable element of the water resource and constitutes a realizable, simple, profitable, operational solution technically. The present study, which is essentially experimental, is interested in the effect of the internal parameters on a double slope plane solar still. In this work, the solar still was conceived and realized by our team of research. The experiments were carried out at different conditions. The variation of the different operating parameters of the solar still has been studied. It is found that the distillate production rate increases when the difference between the temperature of water and glass decreases. Distillated water was also, influenced by the presence of wind and the climatic changes which decrease the amount of diffuse solar energy received by the brackish water. The average yield of distilled water was 4 L/m2 /day. [Copyright &y& Elsevier]