Sprayable and pumpable urea silicate foam for pipe pillows, trench breakers and civil construction applications

A method for supporting a pipe in a trench comprising the steps of:

• a) providing, separately, a component A and a component B, wherein component A comprises at least 23% by weight of alkali silicate and a catalyst and component B comprises at least 75% by weight of at least one polyisocyanate and a block copolymer according to general formula I, based on the total weight of component A and component B, respectively, wherein formula I comprises
• wherein P comprises a polyether having a structure of —((CH2)2O)x(CH2)3O)y—R
• wherein n, m, x and y are integers and R is either a H or an alkyl group;
• b) combining component A with component B thereby forming a urea-silicate foam material;
• c) placing a support material in the bottom of the trench, the support material being electrically conductive when wet and the support material being biodegradable;
• d) placing a pipe into the trench;
• and
• e) depositing the urea-silicate foam material into the trench onto the support material and over a portion of the pipe and allowing it to foam and cure on the support material and around a portion of the pipe thereby forming a urea-silicate foam trench breaker in the trench, wherein said urea-silicate foam trench breaker has an open cell content of at least 50%, is electrically conductive and permeable to water.