Recently, a new type of water soluble resin (a sodium sulfonate of a special polymerized product of melamine and formaldehyde) has been used as an admixture for mortars and concretes. The admixture has an excellent effect on reducing water cement ratio in the concrete mix. then every property of concretes are improved, especially high early strength is remarkable.
In this paper, various properties of the concrete admixed the resin polymer are described on reference to some literatures in the past and author's experiments, and examples of an application to special concrete tecqunics, such as precast concrete, pumping concrete and durable concrete and so on, are given.

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Light-weight concrete, made of pelletized expanded shale aggregate, was pumped without the aid of boosters as high as 102 m straight up on the 29 story Yokohama Tenrikyokan Bldg..
On taller story above the 17th, concrete was pumped by IHI-PTF-85 T piston type concrete pump, in 5 inch pipelines. Change of properties of fresh concrete after pumping was not excessive, with low loss of slump and 0.5% decrease of air content. However, compressive strength tends to decrease, and drying shrinkage tends to increase slightly after pumping.
When concrete was pumped up to the 29th floor, hydraulic oil pressure of pump reached as high as 173 kg/cm² (e.i. 33 kg/cm² in the concrete cylinders) and pumping rate reached as much as 36 m³/h. The authors estimate that pumping up as high as 120 m will be possible, when other conditions are equal.

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