After that a flexural test will be done using a three point bending method. The main objective of this experiment is to expand the knowledge about the GFRP and its behaviour. Glass fibre reinforced unsaturated polyester (GFRP) were subjected to water immersion tests to know the results of the water absorption on the mechanical properties. 20 specimens with 10cm long of GFRP were used to this experiment, measuring their weight under different types of water and temperatures. Salt water and normal water was under 20c and 60c temperatures. The weight of these specimens was taken during a different time periods. The weight of the GFRP specimens was increased slightly in both types of water for a few days until it was stable. After that a flexural test (three point bending test) was done on these GFRP specimens. (H Dhakal, Z Zhang, M Richardson, 2006) Equipment 1: Water absorption test The absorption of water for the Glass fibre-reinforced polyester (GFRP) remains the key mechanism for degrading mechanical property in this experiment. A water bath machine as in the figure (ten) and two cups of glass as on the figure (eleven) were used in this experiment. The water bath has 6oc water and the two cups were at 20c water temperature. The weights of one single specimen from each group were taken in a different time periods.
Group 1 and 2 were in two jars marked with A and B as on the figure (thirteen). Jar A was containing fresh water and jar B was containing salt water. The 2 jars were inside a water bath machine at 60c water temperature. Group 3 and 4 were in two cups of glass marked with A and B as on figure (eleven). Cup A was containing fresh water at 20c and cup B was containing salt water at 20c as well. Every group has five specimens. The weights of one single specimen from each group were taken in a different time periods using a sensitive scale as on figure (fourteen). At the first day the weight was taken every hour for 6 hours. After that the weight was taken once every day until the weight is settled. At the end the flexural test was done for all the specimens and every specimen has its own flexural graph. Figure thirteen: jars at 60c temperature Figure fourteen: sensitive scale Results and Discussion: Water absorption test Water absorption test were conducted by immersing the GFRP specimens in de-ionised water and salt water. The water bath machine at 60c was containing 2 groups, group 1 was in A jar containing a normal water and group 2 was in B jar containing a salt water. Groups 3 and 4 were at 20c in a glass cups group 3 was in A glass cup containing a normal water and group 4 was in B glass cup containing a salt water. The immersion for the specimens into the water was totally for 144hr. after immersion for 1hr, one specimen from each group were taken out of the water and all surface water was removed with a clean soft dry cloth. The specimens were weighed regularly at 1, 2, 3, 4, 5, 6, 24, 48, 72, up to 144hr. ( H Dhakal, Z Zhang ,M Richardson ,2006) After immersion the GFRP specimens into the water for a week at ambient temperature at 60c and 20c, all