Experimental Research On The Mechanical Properties Of Dry-mixture Materials For Shotcrete

With the social continuously development, the country is high attention to energy saving,emission reduction,environmental protection. On the coal mine roadway construction, field leakage coefficient mix is still possession leading position. Instead of field leakage coefficient mix is the need of development and is necessary. therefore, the test was designed and dry-mixture materials were researched according to the basic mechanics characteristic and shelf life of dry-mixture materials were investigated.According to the main influence factors of dry-mixture materials,basic mechanics property test of dry-mixture materials under different six sand moisture content (0,0.5%,1.0%,3%,5%,7%) is done. It was discovered when the sand moisture content equal 0.5%,1.0% and keeping time of dry-mixture materials is from 0 day to the 15th days, cubic compressive strength reduces partly to 4.9%,8.9%, splitting tensile strength reduces partly to 10.9%,16.3% and keeping time of dry-mixture materials is the 28th days, cubic compressive strength reduces partly to 6.7%,12.0%, splitting tensile strength reduces partly to 15.3%,18.6%; when the sand moisture content equal 3% and keeping time of dry-mixture materials is from 0 day to the first days, cubic compressive strength reduces to14.2% and keeping time of dry-mixture materials is from 0 day to the third days, splitting tensile strength reduces to19.5%. If the allowable strength loss equal 7%, shelf life of dry-mixture materials which the sand moisture content equal 0.5% is 28 days, but it is only 7 days that the sand moisture content equal 1.0%. If the allowable strength loss equal 15%, shelf life of dry-mixture materials which the sand moisture content equal 3% is 1 days, We have field test under Huaibei Mining (group) Co., Ltd and developed shotcrete machine of control dust double stirring stuff and spraying device. When use the dry-mixture materials spraying, Shotcrete has a litter rebound , reduced concrete amount and labor intensity,so work efficiency was improved.