| 摘要 |
PURPOSE: A manufacturing method of hard burned lime and an anti-crack agent using the same are provided to reduce crack generation amount after construction by compensating initial firing shrinkage and dry shrinkage of dry cement mortar. CONSTITUTION: A manufacturing method of hard burned lime comprises the following step: sintering raw limestone at 1200-1300 deg. Celsius for 24-30 hours. Calcium oxide(CaO) content amount of the hard burned lime is 82% or greater, of unplasticized limestone(CaCO3) is 8% or less, and the plasticity degree is less than 5% based on ignition loss. The maximum exothermic temperature(Tmax) of heat of hydration is less than 45 deg. Celsius and arrival time to the maximum exothermic temperature is 30 minutes or greater. The particle size distribution comprises 90-100% of 100mesh passable particles, 60-70% of 170 mesh passable particles, and 40-50% of 325 mesh passable particles. The crack inhibitor includes cement and 2-10 wt% of the hard burned lime based on the weight of the cement. |
