Clay Aggregate Concrete Mixing and Construction Technology

1. Concrete mixing

(1) When mixing high-performance clay aggregate light aggregate concrete, the mixing personnel are required to feed materials strictly according to the mix ratio.

(2) Timely measure the water content of the sand, adjust the water consumption of concrete mixing, and change the slump of self-compacting concrete must be carried out by on-site technicians, and it is strictly forbidden to increase the water consumption at will;

When mixing clay aggregate concrete, the optimal watering time is also closely related to the order of feeding materials. If a self-falling mixer is used for mixing, the hopper is raised and the water is released in time when the material is just fed, so that the mixing time can be shortened, the mixing is easier, and it is easy to mix evenly. If you add water first or later, it is not easy to stir evenly. Therefore, it is very important to choose the best time to add water. Because clay aggregate has strong water absorption performance, when preparing concrete, the total amount of water added is larger than that of ordinary concrete, and the water absorption of clay aggregate for 15 minutes is generally increased.

(3) Concrete mixing time The mixing time of clay aggregate concrete should be longer than that of ordinary concrete. If a forced mixer is used for mixing, the concrete mixing time should be strictly controlled at 120~160s. If a self-falling mixer is used, the mixing time can be controlled at 160~240s to ensure that the concrete mixture is evenly mixed and the work-ability of the mixture meets the aforementioned quality requirements.

(4) Requirements for concrete mixture Control the concrete slump to (160+-20)mm. In order to ensure the pouring quality, strength and durability of concrete, it is required that the concrete mixture does not bleed and has good work-ability.

(5) Selection of clay aggregate concrete mixer Since clay aggregate is light and easy to float, it is not easy to mix evenly, so it is best to choose equipment with better mixing performance, such as forced mixer.

(6) When mixing clay aggregate concrete, there are currently two ways to add water.

a. Pre-sprinkle the clay aggregate with water until it is almost saturated, then mix the ingredients and mix, and only add the effective amount of water during the formal mixing. The advantage of this method is that the combination is relatively stable; the disadvantage is that the concrete is prepared after the clay aggregate absorbs water, and the strength of the concrete decreases. .

b. The clay aggregate in the natural dry state is directly used for batching and stirring, and the total water consumption is added to the formal stirring. The advantage of this method is that the strength of the prepared concrete is high, and the disadvantage is that the quality of the mix is not easy to stabilize.