Shandong Laiwu City of waterproof board manufacturers introduced the principle of expansion joint expansion joint water leakage of water leakage process technology works: basic principles waterproof plugging construction method used is chemical grouting. Whatever leakage, how the water can be controlled in a short time. Chemical grouting is the use of manual or mechanical means, carried with water, plugging, under pressure, will be a special chemical grouting material poured into the cracks in the building structure, so that solidified in cracks in the grouting material to reach the filling and sealing cracks purposes. Whatever leakage, how the water can be controlled in a short time. For through the cracks, it can be taken Sealing, pipe, chemical grouting method for processing. Non through the cracks, because the relationship between breath, difficulty filling the slurry into cracks steeple area, and thus can not eliminate the stress concentration area formed by the tip region, so treatment should be carefully considered a variety of factors, improving the slurry filling rate. For temperature crack, taking into account the temperature of the concrete construction of the "lag effect" generally choose low temperature of the concrete grouting plugging water seepage good effect.