Accelerating set times of flowable fill compositions with dry calcium chloride, and methods of utilizing and producing the same

Abstract

Fast-setting Portland cement compositions for filling voids, such as mine shafts and excavated utility trenches, are described. The Portland cement compositions set quickly and are useful when traditional slow setting compositions are less desirable. The acceleration of the set time results from the addition of dry calcium chloride to the Portland cement composition. The compositions consist of Portland cement, dry calcium chloride, water and sometimes preformed cellular foam. Some compositions can include also include fly ash. The compositions may have a compressive strength of between 0 psi and 30 psi after 4 hours, a compressive strength of between 30 psi and 120 psi after 24 hours, a compressive strength of between 200 psi and 500 psi after 28 days, a penetration resistance of between 0.1 tsf and 5 tsf after 10 hours, a penetration resistance of between 0.8 tsf and 10 tsf after 24 hours, and a removability modulus of between 0.2 and 1.0 after 28 days. Also disclosed are methods of filling a void with fast-setting Portland cement.