A Researh On Reinforcing Concrete Epoxies/Fibre Compound System And Its Performance

Concrete structure is widely used in civil engineering because of its good mechanical performance and low cost. However, due to the corrosion of steel which is exposed in erosive environment, the deterioration of concrete, the need of improvement of the original design, and severe happenstances such as earthquakes, fire, and collisions of automobiles or ships, the structure can't satisfy the functional requirement any more. Then it needs reinforcing and strenghtening. Traditional methods like pillar strenthening, enlarging the sectional plane, and cladding outer steel takes lots of time, space, and large scale construction equipment, which impacts the normal use of the structure and causes economic losses directly or indirectly. Fibre Reinforced Plastic(FRP) is a new constructional material. Its high intensity, low weight and readiness to cut and use makes it popular in reinforcing and strenghtening concrete stucture. Currently the use of this new material is mature in Japan and the USA. China has started research on FRP since late 1990s. The current emphasis is reinforcing conrete structure with FRP material pasted outside, whose construction period is shorter and workload is less (just a few people'hand operation is OK). And it also has a good durability and quality of construction. Based on the dvantages above, it has been paid close attention to by insiders.This article deals with the research of epoxy system used to splice reinforcing concrete based on the analysis of the methods of splicing concrete. The proper epoxy system used to splice concrete is prepared to satisfy the construction requirements of reinforcing building construction with the composite material of carbonform and fibre glass. Labilizing calcium carbonate by using coupling agent KH-550 so as to better the disperstiveness of calcium carbonate in materials and connect the interfaces of materials and make provements. Kinds of tests are used to illustrate the effect and mechanism of toughening modification.Research of the gel time, curing degree, Shore-D, and mechanical properties of epoxy systems solidified with different volumes of curing agent is made, and preliminary analysis of curing mechanism are made, through which the best volume is determined. Analysis of micro-characteristics of carlcium carbonate/epoxy composite are done by using SEM. The results are as follows. The fracture surface of pure epoxy is even, with no plastic deformation on it, which is typical brittle fracture. So the mechanical property is relatively low. In contrast, the fracture surface of the composite with calcium carbonate in it is rough, whose epoxies obviously glide and jut on the impact direction. Calcium and its surrounding interfaces of epoxies cause splay, which proves that an extensive plastic deformation occurs to the epoxy, and that the occurance takes in plenty of impact energy, and thus improves the toughness of the compound system. Then, researches are done on mechanical properties of the prepared epoxy compound materials with equipment like multi-use mechanical testing machine and so on. And the relative results are as follows. The tensile-strength and impact strength of the epoxy is 42.3MPa and 10.11 KJ/m2 when there is no calcium carbonate added. As the added calcium carbonate increases, the impact strength of composite materials increases gradually. And the max. Appears when the proportion of the quantities of calcium carbonate and the epoxy is 5:100, and the numbers are 78.8MPa and 17.4KJ/m2, and both tensile-strength and impact strength of the epoxy reaches the peak. This proves that adding calcium carbonate can improve tensile-strength and impact strength of the epoxy. The microcosmic and macrographic researches above shows that calcium carbonate/epoxy compound system can be used to splice reinforcing crete.The article also deals with the splicing performance of the fiber cloth and concrete after epoxy compound system is spliced. The main performance indexes of the test piece is analysed. Based on a contrast of the proporties between of the two kinds of fibre, by resolving the destructive conditions of the sample through bending test, analyse the influence of the toughened and modifiedepoxy compound system on splicing performance and strengthening effects, and the influence of splicing thickness on the properties of the reinforced concrete. The test shows that fibre glass is a ideal strengthening material to members in bending which requires high ductility. To those members in bending that requires high rigidity rather than ductility, and whose ultimate bearing capacity is not so high, carbonform, multilayer fibre glass and multilayer fibre glass pasted in pieces are good materials. At last, contrastive analysis is made from the perspective of economic efficiency. To get the same effects, the reinforcing cost of glass cloth per square meter is much less than that of carbonform.