Method for detecting polyacrylamide in machine-made sand

Abstract

The invention discloses a method for detecting polyacrylamide in machine-made sand. The method comprises the following steps: A, mixing standard machine-made sand, cement and water to form standard mortar; B, adding polyacrylamide into the standard mortar until the mortar expansion degree of the standard mortar reaches a set value, and recording the addition amount W0 of the polyacrylamide at the moment; C, mixing the sieved to-be-detected machine-made sand, cement and water to form to-be-detected mortar; D, adding polyacrylamide into the mortar to be detected until the mortar expansion degree of the mortar to be detected is equal to the mortar expansion degree of the standard mortar in the step B, and recording the addition amount W1 of the polyacrylamide at the moment; and F, calculating the absolute value of W of the difference value between the W0 and the W1, and judging whether the polyacrylamide content in the machine-made sand is qualified or not according to the numerical value of the absolute value of W. The method for detecting the polyacrylamide in the machine-made sand, provided by the technical scheme, is beneficial to simply and quickly detecting the residual quantity of the polyacrylamide in the machine-made sand, and is simple in steps and high in operability.

Description

technical field [0001] The invention relates to the technical field of hydraulic engineering detection, in particular to a detection method for polyacrylamide in machine-made sand. Background technique [0002] Sand is the main material of concrete. It is generally called fine aggregate in construction. It plays a filling role in concrete products, can improve the compactness of concrete, and has a great influence on the performance of concrete. There are mainly two types of sand: natural sand and machine-made sand. At present, the construction sand in my country is still dominated by natural sand. However, with the development of the construction industry and the emphasis on the quality of construction projects, the amount of sand used in the construction market is also increasing. At the same time, the quality requirements are also getting higher and higher, and qualified natural sand resources are becoming less and less. Especially for Yunnan and Guizhou, where natural s...

AI Technical Summary

Problems solved by technology

[0003] Due to the good flocculation effect of polyacrylamide (PAM), it is often used as a flocculant in sand washing plants. During the sand washing process, the powder in the sand is washed off and enters the waste water. In order to improve the utilization rate of water , the sand washing plant will add flocculants to the wastewater, so that the powder in the wastewater can be precipitated, and then the wastewater will be used for sand washing again. Because the wastewater is recycled, the wastewater will also be mixed with polyacrylamide , so that polyacrylamide will remain in the sand and gravel. A small amount of polyacrylamide can improve the workability of concrete, but when the amount of polyacrylamide in concrete is excessive, it will seriously affect the workability of concrete. Impact

[0004] The existing concrete with polyacrylamide is mainly used for underwater concrete, which is helpful for concrete flocculation. At the same time, the existing commercial mixing station adds less polyacrylamide to the concrete, and the amount of polyacrylamide in the sand is still the same. It will affect the workability of concrete. Therefore, the content of polyacrylamide in sand is very important to the influence of concrete construction performance, but there is no method for accurately detecting residual polyacrylamide in machine-made sand.