Fundamental reasons: ① After on-site experiments, the key factor affecting the properties of polycarboxylate superplasticizer concrete in the stone is the mud content of the stone. As the mud content increases, the rheological properties of the concrete will decrease. At the same time, the clay type, silt sand, and lime powder in the stone also have a great impact on the adaptability of the polycarboxylate superplasticizer. ② The key to the impact adaptability of external admixtures is the loss on ignition and particle size of the external admixtures. The greater the loss on ignition, the faster the rheology of the concrete will be damaged. ③ Hydrated lime is a by-product of power stations, and different coal qualities have a great impact on the mixture properties of concrete.
Countermeasures: ① Use qualified stone or clean the stone. ② Within a certain range, the harm of mud content can be reduced as much as possible according to the method of reducing sand rate. ③Try to select admixtures with small loss on ignition while considering technical standards. ④ When using about two kinds of admixtures, try to avoid the dosage of the external admixture that will cause poor adaptability of the admixture. ⑤Maintaining the relative stability of coal sources is a key strategy to improve its adaptability.
The impact of stamping process factors on adaptability. The early characteristics of recycled concrete directly affect the properties and performance of the hardened concrete, especially the air content; when the concrete has been transported and transported for tens of meters, In high-temperature environment, its early workability and rheological characteristics will change greatly, and the air content will be greatly damaged, resulting in the reduction of concrete flowability, pumpability and sudden drop in performance. Correct feeding sequence and appropriate mixing time are important factors affecting the properties of concrete mixtures. Especially during the winter application period, it is very necessary to adjust the feeding sequence in time and increase the mixing time in accordance with relevant regulations. When transporting by concrete tanker, the re-adding method can be used 10 minutes before concrete pouring. This will not reduce the performance of the concrete and improve the rheological properties, which is very practical.
In other words, the integration problem of polycarboxylate water-reducing agent is far more complicated than that of naphthalene-based water-reducing agent. To solve its integration problem, it must be treated with a systematic and transformational perspective while analyzing it in depth. The adaptability problem is solved, and the concept of mutual integration between the water-reducing agent and the various components of the concrete is established.
</p
微信扫一扫打赏
