Resin concretes

McCurrich, L. H. and Kay, W. M., Polyester and epoxy resin concrete, paper presented at the Symposium on Resins and Concrete, University of Newcastle-upon-Tyne, 17-18 April (1973). 

In the melted state elementary sulfur is an excellent binder for aggregates such as sand, gravel, crushed stone, and similar materials. When a hot sulfur aggregate mixture is left to set, a material of concretelike hardness is obtained. This property leads to the term sulfur concrete or sulfur mortar, which is wrong strictly speaking, since the word concrete is used to refer to a product in which aggregates are bound with hydraulic products such as cement or with limestone. However, since polymer-bound aggregates recently developed to industrial maturity have been called polymer or synthetic resin concrete, the term sulfur concrete is maintained in this chapter. 

PET is useful polymer used for fiber, film, and plastic containers such as carbonated beverage bottles. Recently, the recycling of polymers such as PET after use is attracting the attention of many researchers aware of environmental problems and wishing to find ways to save earth resources. Previous studies showed that unsaturated polyester resins can be economically prepared from recycled PET and the resins may be useful for resin concretes (1 4). However, there is little information on the molecular features of the UPE resins. Thus, we synthesized various UPE resins from PET. Especially, the PET content, chain flexibility and degree of unsaturation of the resins were systematically varied and the effects of those variables on the mechanical properties of the cured resins and polymer mortars made therefrom were studied. 

Mixing into (polyester resin concrete) as filler material replacing CaC03 or aggregates (sands, small or middle)... 

Polyester resin concrete was mixed and molded to the desired specimens according to JIS A 1181 (Method of Making Polyester Resin Concrete Specimens) at 20°C, 50% R.H. The formulations of its binder and the mix proportion are given in Tables m and IV respectively. Size of the specimens was 01Ox2Oc,m. Then the specimens were cured at 20°C, 50% R.H. for the desired curing time. 

Embedded strain gages with 100mm of gage length, were Installed in polyester resin concrete when the specimens were molded. The length change was measured by static strain meter connected with a timer at 20°C, 50 % R.H. The measurements were conducted at Intervals of 5 minutes for 60 minutes after adding the catalyst to... 

OHAMA ET AL. Length Change of Polyester Resin Concrete... 

Table HI. Formulations of Binder for Polyester Resin Concrete.

Fig. A shows the effects of CoOc and MEKPO contents on setting shrinkage of polyester resin concrete. The setting shrinkage increases with rising contents of CoOc and MEKPO. In particular, the shrinkage is remarkably affected by MEKPO (catalyst) content rather than CoOc (accelerator) content.

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...

Figure 9. Content of shrinkage-reducing agent vs. 24-hr length change of polyester resin concrete...

Fig. 10 shows the comparison of data on setting shrinkage of polyester resin concrete determined by the experimental automatic apparatus and embedded strain gages. 

The setting shrinkage of polyester resin concrete increases with a rise in contents of catalyst and accelerator, and is markedly affected by catalyst content rather than accelerator content. 

The shrinkage of polyester resin concrete decreases with increasing content of styrene contained in its binder. 

Y. Ohama, K. Demura and M. Komiyama Properties of polyester resin concrete with various styrene contents, in Proceedings of the 22nd Japan Congress on Materials Research, The Society of Materials Science, Japan, Kyoto (1979), pp.360-363. 

Y. Ohama, K. Demura and T. Kobayashi Mix proportioning and mechanical properties of polymethyl methacrylate resin concrete. Transactions of the Japan Concrete Institute Vol.3 (1981), pp.97-104. 

Y. Ohama Determination methods for working life of polyester resin concrete, in Polymers in Concrete, SP-58, American Concrete Institute, Detroit (1978), pp.31-40. 

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