水泥砖制备
Preparation of cement brick
1、混料时间：混料时间长就能混均匀。干混料20分钟比10分钟的强度提高15—23%；湿混料时间以物料不结块为宜。混合好的料存放时间以2小时左右为宜，时间太长或太短，都会降低砖的抗压强度。
1. Mixing time: mixing time can be even if mixing time is long. The strength of dry mixture in 20 minutes is 15-23% higher than that in 10 minutes, and the best time for wet mixing is not caking. The best storage time of mixed materials is about 2 hours. If the time is too long or too short, the compressive strength of bricks will be reduced.
2、成型压力：粘土水泥砖成型时的压力，以每平方厘米500公斤最好。在此压力下，其制品抗压强度高，耐水性能好。压力太低，不易压实。
2. Molding pressure: clay cement brick molding pressure, 500 kg per square centimeter is the best. Under this pressure, the product has high compressive strength and good water resistance. The pressure is too low to be compacted easily.
3、养护条件：水泥砖又称免烧砖，成型后再自然环境中淋水养护即可，养护7天龄期的强度，相当于28天龄期强度的67—90%；28天龄期强度为一个季度龄期强度的80—95%。故如养护场地小，水泥砖自然养护7天后就可出厂。
3. Curing conditions: Cement brick, also known as non fired brick, can be cured by pouring water in natural environment after molding. The strength of 7-day curing is equivalent to 67-90% of 28 day strength, and 28 day strength is 80-95% of that of a quarter. Therefore, if the maintenance site is small, the cement brick can be delivered after natural curing for 7 days.