Effects of Meta-Kaolin Clay on the Working and Strength Properties of Cement Grouts

Abstract

In this study the effects of meta-kaolin clay on the setting time, bleeding, flow-ability, pullout strength and compressive strength characteristics of cement grouts were investigated. Amount of clay used, varied upto 10% by weight of cement. Setting time was measured using the Vicat’s needle apparatus and the flowability was measured using the Marsh funnel cone viscometer. Setting time marginally decreased with the addition of clay for the grout with w/c ratio of 0.6. However, addition of 3% clay increased the setting time by 22 min for the cement grout with w/c ratio of 1. Also the grout with 10% clay had a longer setting time than the cement grout having 5% clay content. Results showed that the curing temperature and electrical resistivity were not clear indicators of the setting time. Addition of clay decreased the bleeding of the cement grout thereby making the grout stable. Addition of 10% clay to the cement grout with w/c ratio of 0.6 had zero bleeding. Pull-out strengths and compressive strengths of the cement grouts showed notable variations with the addition of clay. Interface shear type failure was observed on all the pull-out tests. INTRODUCTION Cement grouts have multiple applications and hence there is continued interest in modifying the grout (Vipulanandan et al. 1997 and 2000). Various studies have been in progress to modify and improve the composition of cement grouts to enhance the physical and chemical properties of the grout (Ata and Vipulanandan 1997). Several different grout formulations with Portland cement and pulverized fuel ash, sea water, powdered chalk, bentonite and sodium silicate at different proportions have been in use since mid 1970’s for void filling in the foundations of offshore concrete gravity platforms (Domone, 1988; ata et al. 1990). With special qualities such as high water assimilation, good dilution resistance and good rheological behaviors, clay hardening grout have been in common use which had a composition of kaolinite clay and common silicate cement (Xinghua et al, 1997). In this study the gelling time and the plastic strength of the clay hardening grout was studied with respect to varying the composition of the grout mix. Huang (2001) studied the changes in the properties of cement – fly ash grout on addition of polypropylene fiber and superplasticizer. 66 7A _5 08 36 _A S C E _V ol _0 2_ R es iz e_ A A .jo b_ P ro ce ss C ya n_ 07 /3 1/ 20 12 _0 7: 54 :3 4 66 7A _5 08 36 _A S C E _V ol _0 2_ R es iz e_ A A .jo b_ P ro ce ss M ag en ta _0 7/ 31 /2 01 2_ 07 :5 4: 34 66 7A _5 08 36 _A S C E _V ol _0 2_ R es iz e_ A A .jo b_ P ro ce ss Y el lo w _0 7/ 31 /2 01 2_ 07 :5 4: 34 66 7A _5 08 36 _A S C E _V ol _0 2_ R es iz e_ A A .jo b_ P ro ce ss B la ck _0 7/ 31 /2 01 2_ 07 :5 4: 34