Experimental Research And Apply On The Soundless Cracking Agent

The soundless cracking agent (SCA) is a kind of expansive powder which produced expansion of solids and swelling pressure after the hydration reaction, became popular for cutting or cracking rock, concrete, stone and other brittle solid materials. SCA has many advantages in breaking process, which includes no blasting wave, no quake, no noises, no flying stone and no poisonous gas etc. It is an important development and supplement to the traditional blasting technology.In this paper, theoretical analysis was given to the principle of destruction based on elastic mechanics and fracture mechanics, which are studied on the basis of summarizing research status both at home and abroad. Laboratory tests were carried out on the impact of the change of environment temperature on reaction temperature of cracking agent and volume ratio of expansion, when the ambient temperature is high, breaking agent response rate and peak temperature are high, up to 129.TC, before and after reaction volume ratio is large, about 5 times. The maximum expansive pressure range of cracking agent under different temperatures was measured, high ambient temperature can promote expansive pressure rapidly grow in a short time, to a considerable value, the effective maximum expansive pressure of 60-70MPa. Tests were setted on concrete block in different steel fiber content for experimental analysis of static breaking crack. The existence of steel fiber restricts the development of concrete cracks, cracks on the plain concrete block were quadruple of which on the steel fiber reinforced concrete block after 24h. At the same time, the failure mode of concrete block in connection with the volume fraction of steel fiber, usually damaged into 2-4 pieces.Finally, based on experiment, application of soundless cracking agent at special section of construction environment in two coal mines in Huaibei Mining Group, different fragmentation parameters were setted, the corresponding construction technology was constituted, and obtained result. The practice indicats that SCA provides reliable performance, good cracking effect, simple and convenient construction, high safety. It has outstanding economic results and comprehensive practical significance.Figure [53] table [10] reference [54]...