Experimental Study On Mechanics Performance Of The Interface On The BFRP/GFRP Composite Cement Template And The Concrete

In this paper, a permanent cement template which is reinforced by the fiber reinforced polymer pured directly with the concrete together into an "reinforced composite cement template/concrete/reinforced composite cement template" mixed structure. The reinforced composite cement as a part of the mixed structure, can be loaded with the concrete structure together. The composite cement permanent templates not only have the advantages of free demolition and transportation of the formworks, but also can greatly reduce the engineering cost, shorten the construction period, save a large number of the natural resources such as steel, wood and bamboo. But the mechanics performance of the interface between the cement formworks and the concrete is very crucial.There are seven different conditions which might affect on the mechanics performance of the interface to be studied in this paper, and the seven conditions are different types of fiber reinforced polymer, different kinds of the concrete, different concrete strength, different cement template interface treatments, different thickness of the cement template, different ribs on the interface of fiber reinforced polymer composite and different sizes of the specimens. The failure modes, interface stress, the relative slippage and the strain on the interface of the composite cement template and concrete were studied on the seven different conditions in this paper. The main research results show that the application of the fiber reinforced polymer on the cement templates can effectively improve the strength of the cement template and the mechanics performance of the interface between the composite cement template and the concrete; with the increasing of the concrete strength, the boding mechanics performance of the interface is also enhanced; the mechanics performance of the interface between the self-compacting concrete and the composite cement template is higher than that of the interface between the ordinary concrete and the composite cement template; the mechanics performance of the interface can be greatly strengthened by the means of setting ribs on the composite cement template face, especially for the crossing ribs; the mechanics performance of the interface using the glass fiber reinforced polymer is slightly stronger than that of using the basalt fiber reinforced polymer.Based on this, the research also shows that the glass fiber reinforced polymer can be entirely replaced by the basalt fiber reinforced polymer so that the limitation that the glass fiber reinforced polymer has to be used with low alkalinity cement in construction can be avoided. The results of the study further shows that the fiber reinforced polymer especially the basalt fiber reinforced polymer composite cement template was of feasibility for the permanent formwork to mix with the concrete to take the load together. And it provided the theory basic for the further application of the fiber reinforced polymer composite cement template in practical engineering.