TY - JOUR
T1 - Development of High-Performance Fly-Ash-Based Controlled Low-Strength Materials for Backfilling in Metropolitan Cities
AU - Han, Jingyu
AU - Jo, Youngseok
AU - Kim, Yunhee
AU - Kim, Bumjoo
N1 - Publisher Copyright:
© 2023 by the authors.
PY - 2023/8
Y1 - 2023/8
N2 - Controlled low-strength materials (CLSMs) have been developed using various byproducts for backfilling or void-filling around pipelines or culvert boxes. However, these CLSMs have encountered issues related to their inadequate placement around underground facilities, despite satisfying the performance requirements, especially flowability, recommended by the American Concrete Institute (ACI) 229 committee. In this study, a new CLSM is developed to ensure a significantly higher flowability, lower segregation, and faster installation compared with previously developed CLSMs. This is achieved through a series of laboratory tests. To enhance the flowability and prevent segregation, a calcium-sulfoaluminate-based binder and fly ash are used in combination with two types of additives. The measured flowability of the new CLSM is 700 mm, while its compressive strength and bleeding satisfy the general criteria specified by the ACI 229R-13. In addition, the performance of the developed CLSM is compared with that of predeveloped CLSMs. The new CLSM was not only shown to exhibit the highest flowability, but also to satisfy the specified requirements for compressive strength and bleeding. Overall, it is anticipated that the developed CLSM can significantly reduce the costs related to the disposal of old pavements, the installation of new pavements, and other construction expenses compared to the costs related to the conventional method, even though the expenses for the backfill materials could increase due to the higher production costs of CLSMs than soil. In addition, there is a need to investigate its field applicability in order to evaluate the precise costs, maintenance, and long-term stabilities after installation.
AB - Controlled low-strength materials (CLSMs) have been developed using various byproducts for backfilling or void-filling around pipelines or culvert boxes. However, these CLSMs have encountered issues related to their inadequate placement around underground facilities, despite satisfying the performance requirements, especially flowability, recommended by the American Concrete Institute (ACI) 229 committee. In this study, a new CLSM is developed to ensure a significantly higher flowability, lower segregation, and faster installation compared with previously developed CLSMs. This is achieved through a series of laboratory tests. To enhance the flowability and prevent segregation, a calcium-sulfoaluminate-based binder and fly ash are used in combination with two types of additives. The measured flowability of the new CLSM is 700 mm, while its compressive strength and bleeding satisfy the general criteria specified by the ACI 229R-13. In addition, the performance of the developed CLSM is compared with that of predeveloped CLSMs. The new CLSM was not only shown to exhibit the highest flowability, but also to satisfy the specified requirements for compressive strength and bleeding. Overall, it is anticipated that the developed CLSM can significantly reduce the costs related to the disposal of old pavements, the installation of new pavements, and other construction expenses compared to the costs related to the conventional method, even though the expenses for the backfill materials could increase due to the higher production costs of CLSMs than soil. In addition, there is a need to investigate its field applicability in order to evaluate the precise costs, maintenance, and long-term stabilities after installation.
KW - backfilling
KW - calcium-sulfoaluminate-based binder
KW - controlled low-strength material
KW - fly ash
KW - high flowability
UR - http://www.scopus.com/inward/record.url?scp=85169139436&partnerID=8YFLogxK
U2 - 10.3390/app13169377
DO - 10.3390/app13169377
M3 - Article
AN - SCOPUS:85169139436
SN - 2076-3417
VL - 13
JO - Applied Sciences (Switzerland)
JF - Applied Sciences (Switzerland)
IS - 16
M1 - 9377
ER -