污泥陶粒次轻混凝土的制备与性能研究

用碎石和污泥陶粒作为混合粗集料配制了不同集料组成的次轻混凝土试样,系统地研究了它们的力学性能和热学性能。虽然污泥陶粒本身强度不高,但在粗集料中掺入适量污泥陶粒(占粗集料的体积分数x=25%)所制备的次轻混凝土,其早期强度与不掺污泥陶粒的混凝土试样相当。上述现象归结于污泥陶粒与水泥石界面较为致密的组织结构,当其取代碎石集料后,减少了集料与水泥石界面的疏松组织结构,使集料与水泥石界面区的微观结构得到增强。污泥陶粒次轻混凝土的弹性模量介于普通集料混凝土和轻集料混凝土之间,具有比同强度等级普通混凝土更好的延展性,和比轻集料混凝土更高的强度与抗变形能力。与普通混凝土(x=0)相比,当次轻混凝土中x=25%时,其导热系数可降低46%,即掺入少量污泥陶粒可明显提高混凝土的保温隔热性能。

Preparation and performance of specified density concrete using keramzite made from municipal sewage sludge

Specified density concrete(SDC) specimens were prepared using keramizite made from sewage sludge.The batch effects,mainly the proportion of gravel to keramzite,on the mechanical and thermal performance of the as prepared SDC were investigated systematically.Although the essential strength of the keramizite is low,the results indicated that the early compressive strength of SDC was comparable with ordinary aggregate concrete(OAC) when 25%gravel was replaced by keramzite as coarse aggregate(x=25%).The above phenomenon was attributed to the enhanced interface between the aggregate and cement paste that caused by the replacement of gravel with keramzite.The elastic modulus of SDC was between OAC and lightweight aggregate concrete(LAC),implying the SDC had the better ductility than OAC with the same strength level while had higher strength and deformation resistance than LAC.When compared with OAC(x=0),the thermal conducting coefficient of SDC(x=25%) was decreased by 46%,namely a small amount of replacement of gravel by keramzite could result in apparent improvement of heat insulation.