矿物掺合料再生骨料混凝土的力学及耐高温性质研究

Research on Mechanical and High Temperature Resistance Properties of Recycled Aggregate Concrete Containing Mineral Admixtures

为了研究矿物掺合料对再生骨料混凝土的基本特性及耐高温特性的影响,利用飞灰、铁渣和稻壳灰对再生骨料混凝土进行改性,并进行高温和力学实验。结果表明,随着温度的升高,试样的密度和超声波速不断下降;添加法制备的试样的密度和超声波速大于替代法制备的试样;抗压强度和相对弹性模量随着矿物掺量的增加先增后减,在5%~10%时达到较大值。随着温度的增加,抗压强度先增后减,在100℃时达到较大值;且以添加法掺入矿物掺合料时,试样的强度和弹性模量较高。对再生骨料混凝土耐高温性能的增强作用飞灰>铁渣>稻壳灰。此外,采用替代法时混凝土的密度与抗压强度、密度与和弹性模量和超声波速与抗压强度间的相关性较好;而采用添加法时各个参数之间的相关性较差。

To study the influence of mineral admixtures on the basic characteristics and high temperature resistance of recycled aggregate concrete,fly ash,iron slag and rice husk ash were used to modify recycled aggregate concrete.High temperature and mechanical tests were carried out.The results show that with the increase of temperature,the density and ultrasonic velocity of the sample continue to decrease;the density and ultrasonic velocity of the sample prepared by the additive method are greater than that of the sample prepared by the alternative method;the compressive strength and relative elastic modulus increase first and then decreases with the increase of the mineral,reaching the maximum at 5%~10%.As the temperature increases,the compressive strength first increases and then decreases,reaching the maximum at 100°C;and when the mineral admixture is added by the additive method,the strength and elastic modulus of the sample are higher.Enhancement of high temperature resistance of recycled aggregate concrete:fly ash>iron slag>rice husk ash.In addition,the concrete density and compressive strength,density and elastic modulus,ultrasonic velocity and compressive strength have a better correlation when using the alternative method;however,the correlation between the various parameters is poor when the additive method is used.