Research on the Performance of Reservoir Sediment Pervious Concrete Based on Orthogonal Test and Ultrasonic Pulse Velocity.

The reservoir sediment is formed by the combination and precipitation of clay, sand, organic nutrients and inorganic minerals in the reservoir. The reservoir sediment usually exists in the form of irregular and heterogeneous clay glue, which is in a fluid plastic state with good plasticity and relatively loose between particles. The accumulation of sediment in the reservoir will weaken the water storage and flood control capacity of the reservoir, and then reduce the capacity of the reservoir, shorten the life of the reservoir, and affect the shipping traffic. In addition, the long-term accumulation of reservoir sediment may cause pollution to the surrounding environment and reduce the water environment safety index, thus posing a potential threat to human survival. Therefore, it is urgent to make resource utilization of reservoir sediment. In order to improve the added value utilization rate of reservoir sediment in the field of building materials, this paper uses the reservoir sediment as auxiliary cementing material to prepare pervious concrete. Through the orthogonal test, the mix ratio design optimization of pervious concrete with reservoir sediment is studied, and the effects of slag powder, reservoir sediment and reinforcement agents on the performance indexes of pervious concrete with reservoir sediment, such as dry density, total porosity, effective porosity, permeability coefficient, ultrasonic pulse velocity and 28 d compressive strength are analyzed. The relationship between ultrasonic pulse velocity and porosity, permeability coefficient and 28 d compressive strength is studied, and the evolution law of the quality of the specimen and ultrasonic pulse velocity with the number of freeze-thaw cycles is explored. The results show that the dry density, compressive strength and ultrasonic pulse velocity of pervious concrete decrease continuously with the addition of reservoir sediment, and the porosity and permeability coefficient increase continuously. When slag powder is added, the dry density, compressive strength and ultrasonic pulse velocity of the specimen first increase and then decrease, and the porosity and permeability coefficient first decrease and then increase. The reinforcement agent has no obvious effect on the performance index of the specimen. The curve fitting of ultrasonic pulse velocity with porosity, permeability coefficient and 28 d compressive strength is well correlated. With the increase in the number of freeze-thaw cycles, the quality loss rate of the specimen increases gradually, the ultrasonic wave speed decreases gradually, and the slag powder and reinforcing agent can improve the freeze--thaw durability of the specimen. The research findings will promote the development and application of reservoir sediment in the preparation of building materials, and is expected to serve as a reference for the further application of reservoir sediment permeable concrete. [ABSTRACT FROM AUTHOR]