A Study on Curing Properties of Concrete of Containing Large Quantity of Fly Ash

(1)室内试验本研究对大掺量粉煤灰混凝土在40℃空气养护条件下的强度进行了两个水平(普通强度混凝土区和高强混凝土区的单位体积混凝土水泥含量)的强度试验。主要结论如下。当粉煤灰掺量过大时，单位体积混凝土的水泥掺量较大时，抗压强度没有得到提高。当单位体积水泥掺量较大时，当单位体积混凝土中掺入的飞灰掺量达到100 kg/m~3左右时，混凝土的抗压强度表现最佳。即使它再把它们混合在一起，效果也是微乎其微的。在标准养护条件下，混凝土单位体积水泥含量在600 kg/m~3以上时的抗压强度约为100N/mm~2。但混凝土在40℃空气养护下的抗压强度很高，约为80N/mm~2。当混凝土掺入单位体积混凝土中的飞灰含量约为200 kg/m~3时，40℃空气养护混凝土的抗压强度与标准养护时的抗压强度(本试验中为110N/m~2)几乎相同。(2)在冲绳县预拌混凝土生产厂的预拌混凝土厂进行了试验，对冲绳县出厂的飞灰进行了成浆处理。采用大掺量粉煤灰浆混凝土制作了模拟柱状试件。并对其强度特性进行了阐述。主要结论如下。在预拌混凝土厂的实际搅拌试验中，大掺量粉煤灰浆体混凝土的抗压强度高于不掺粉煤灰浆体混凝土的抗压强度。

(1) The Laboratory ExperimentIn this study, it was experimented concerning the strength of concrete containing large quantity of fly ash under 40 degrees centigrade air curing was severe with concrete, in two levels (cement content per unit volume of concrete of the normal strength concrete area and the high-strength concrete area). The conclusions are as follows. When the mixed quantity of fly ash was too large, it was clarified not to show the compressive strength improvement when the cement content per unit volume of concrete was large. When it mixed with concrete up to the fly ash content per unit volume of concrete about 100 kg/m^3 when the cement content per unit volume of concrete was large, and it made it to standard curing, the expression of compressive strength was optimal. And the effect is a little even if it mixes it any more. The compressive strength of concrete at the cement content per unit volume of concrete 600kg/m^3 or more showed about 100N/mm^2 in standard curing. But compressive strength under 40 degrees centigrade air curing was severe with concrete was shown about 80N/mm^2. When it mixed with concrete up to the fly ash content per unit volume of concrete about 200 kg/m^3, the concrete of 40 degrees centigrade air curing showed almost same compressive strength (110N/m^2 in this experiment)as standard curing.(2) Experiment at Ready-mixed Concrete PlantIn the ready mixed concrete producer in Okinawa Prefecture, The fly ash exhausted in Okinawa Prefecture was slurried. The simulated column specimen was made by using concrete containing large quantity fly ash slurry. And the strength properties of it was clarified. The conclusions are as follows. In actual mixer experiment at ready-mixed concrete plant, the concrete containing large quantity the fly ash slurry showed compressive strength that was higher than the concrete no containing fly ash slurry.