Next Article in Journal
Carbon-Efficient Virtual Machine Placement Based on Dynamic Voltage Frequency Scaling in Geo-Distributed Cloud Data Centers
Next Article in Special Issue
Experimental Characterization of Prefabricated Bridge Deck Panels Prepared with Prestressed and Sustainable Ultra-High Performance Concrete
Previous Article in Journal
Real-Time FPGA-Based Balance Control Method for a Humanoid Robot Pushed by External Forces
Previous Article in Special Issue
High Performance Self-Compacting Concrete with Electric Arc Furnace Slag Aggregate and Cupola Slag Powder
Article

Economic and Technical Viability of Using Shotcrete with Coarse Recycled Concrete Aggregates in Deep Tunnels

1
Instituto Superior Técnico, Universidade de Lisboa, 1649-004 Lisbon, Portugal
2
CERIS, Setúbal’s Polytechnic Institute, 2910-761 Setúbal, Portugal
*
Author to whom correspondence should be addressed.
Appl. Sci. 2020, 10(8), 2697; https://doi.org/10.3390/app10082697
Received: 10 February 2020 / Revised: 26 March 2020 / Accepted: 3 April 2020 / Published: 14 April 2020
(This article belongs to the Special Issue High-Performance Eco-Efficient Concrete)
This work analyzes the technical and economic viability of using coarse recycled aggregates from crushed concrete in shotcrete, as a primary lining support in tunnels. Four incorporation ratios of coarse natural aggregate (CNA) with coarse recycled concrete aggregates from concrete (CRCA) were studied: 0%, 20%, 50% and 100%. The mechanical properties of the dry-mix shotcrete were obtained in an independent experimental campaign. Initially, the technical viability of CRCA shotcrete was validated for deep rock tunnels, based on the convergence-confinement method. Two cases were studied to determine the equivalent thickness for each combination of replacement ratio using CRCA shotcrete: (i) similar stiffness and (ii) similar yield stress. Subsequently, an economic assessment was performed. The stiffness criterion increased the thickness below 10% in both the 20% and 50% replacement ratios, which shows their technical viability with very marginal cost increase (<5%). On the other hand, the maximum pressure criteria required higher increments, close to 30% in the 50% replacement ratio. A full replacement was proven to be impracticable in both analyses. View Full-Text
Keywords: shotcrete; deep tunnels; convergence-confinement method; coarse recycled concrete aggregate; dry-mix process shotcrete; deep tunnels; convergence-confinement method; coarse recycled concrete aggregate; dry-mix process
Show Figures

Figure 1

MDPI and ACS Style

Duarte, G.; Carrilho Gomes, R.C.; de Brito, J.d.; Bravo, M.; Nobre, J. Economic and Technical Viability of Using Shotcrete with Coarse Recycled Concrete Aggregates in Deep Tunnels. Appl. Sci. 2020, 10, 2697. https://doi.org/10.3390/app10082697

AMA Style

Duarte G, Carrilho Gomes RC, de Brito Jd, Bravo M, Nobre J. Economic and Technical Viability of Using Shotcrete with Coarse Recycled Concrete Aggregates in Deep Tunnels. Applied Sciences. 2020; 10(8):2697. https://doi.org/10.3390/app10082697

Chicago/Turabian Style

Duarte, Gonçalo; Carrilho Gomes, Rui C.; de Brito, Jorge d.; Bravo, Miguel; Nobre, José. 2020. "Economic and Technical Viability of Using Shotcrete with Coarse Recycled Concrete Aggregates in Deep Tunnels" Appl. Sci. 10, no. 8: 2697. https://doi.org/10.3390/app10082697

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop