Curing resin concrete with

At 2 to 3 hours of the curing time, slight expansion of polyester resin concrete with 0.5 phr catalyst and 0.5 phr accelerator is attributed to the looseness of compaction due to the setting retardation of the concrete. 

Figure 7. Relationship between curing time and length change of UP-1 resin concrete with various contents of shrinkage-reducing agents...

Possible concerns arise over the potential property mismatch between the repair material and the substrate concrete. Short-term problems may arise because the repair material contracts on curing relative to the surrounding concrete. With resin based mortars the... 

Mitsubishi Chemical manufactures a seismic retrofit material Replark and have formed a joint venture with Fiberite in the USA. Replark is a UD carbon fiber tape with low epoxy resin content with a fiberglass scrim backing to facilitate handling in the field. The application entails the preparation of the concrete, application of an epoxy primer, putty and resin, followed by the requisite number of layers of Replark tape and additional resin, to form a cured composite and finally, the application of a surface coat to improve the appearance. Fiberite use type 12k T300 or AS4C carbon fiber and the Replark is offered in areal weights from 175 300 gm . ... 

Recent developments in the construction and civil engineering industry include the development of intelligent concrete with self-healing capability in Japan (249). Some of the systems are based on epoxy resins encapsulated in concrete which when triggered by cracks open and cure to repair the concrete. 

Table 1 shows the specifications of the concrete, carbon fiber sheet and adhesive resin investigated in the present work. The concrete blocks of 30 x 20 x 90 mm were made of normal grade Portland cement and cured in water for 4 weeks. The carbon fiber sheet (UT70-30, Toray) was a unidirectional cloth bound with a few lateral fibers. The adhesive resin (DK-530, Denka) was a modified acrylic resin of two component system. 

Two concrete blocks were carefully bonded by inserting a carbon fiber sheet with the adhesive resin and cured at room temperature for 48 hours as the manufacturer s recommendation. A thin releasing film was inserted between the concrete blocks and carbon fiber sheet to introduce an artificial crack and to make an adhesive region of 20 x 10 mm The blocks were then bonded to the steel jigs with the same adhesive resin, as shown in Fig. 11. A liquid type primer was used to gain the adhesiveness of the interface between the concrete and carbon fiber sheet. 

The rate of curing depends primarily on the reactivity of the resin and curing agent. It is also dependent on the quantity of mix and on temperature. The materials used in the construction industry that can be bonded with epoxy resin adhesives are metals and metal alloys, concrete, natural stone, fibre cement and plaster, ceramic materials, glass, china and porcelain and wood. 

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