Properties of Slurry Shield Tunnel Sand and Its Application in Large Flow Concrete

Ba Hezhuoli Ke Zierkailedi; Libo Bian; Xiufang Wang; Xingbo Hu; Xuelei Liu; Zhi Zhang

doi:10.3390/ma15155131

Properties of Slurry Shield Tunnel Sand and Its Application in Large Flow Concrete

Materials (Basel). 2022 Jul 23;15(15):5131. doi: 10.3390/ma15155131.

Authors

Ba Hezhuoli Ke Zierkailedi¹, Libo Bian¹, Xiufang Wang¹, Xingbo Hu², Xuelei Liu², Zhi Zhang³

Affiliations

¹ School of Civil and Traffic Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China.
² Beijing Shou Fa Tian Ren Ecological Landscape Co., Ltd., Beijing 100000, China.
³ Beijing Shou Fa Expressway Construction Management Co., Ltd., Beijing 100000, China.

Abstract

The amount of Slurry shield tunnel slag (SSTS) from the Beijing East Sixth Ring Road renovation project is about 3 million m³, and it is mainly fine and silt sand. In order to realize its resource utilization, the properties of SSTS and the performance of concrete with strength grades from C30-C60, which used the mixed sand compound with SSTS and Coarse Manufactured Sand (CMS) as a fine aggregate, were investigated. The results showed that SSTS' fineness modulus is 1.2, its clay content is 17.0% but its composition is mainly Inert Silt (IS), and SSTS replaced with 40% of the mass of CMS can obtain a mixed sand with a fineness modulus of 2.7 and a clay content of 7.0%. The morphological and filling effects of SSTS and IS will improve the workability and durability properties of concrete with no adverse effects on the compressive strength. On the other hand, clay lumps in SSTS adversely affect the workability, early cracking properties, and freeze resistance of concrete, which can be alleviated by dewatering and crushing the clay lumps in SSTS.

Keywords: clay and clay lumps; durability; inert silt; mechanical properties; mixed sand; slurry shield tunnel sand; tunnel slag; workability.

Grants and funding

This research study was funded the Natural Sciences Foundation of China Under Grant (No. 51808025), the Pyramid Talent Training Project of BUCEA (No. JDYC20200329).