TY - GEN
T1 - Improving the spacer-concrete interface for bond strength and durability
AU - Muslim, F.
AU - Wong, H. S.
AU - Buenfeld, N. R.
N1 - Funding Information:
F. Muslim gratefully acknowledges the financial support for her PhD study provided by the Indonesian Endowment Fund for Education (LPDP). We thank Mr. Andrew Morris for his help with the laboratory work.
Publisher Copyright:
© ICDCS 2018. All rights reserved.
PY - 2018
Y1 - 2018
N2 - Spacers are important devices in reinforced concrete that are used to support reinforcing steel during concreting in order to achieve the required concrete cover. They are placed at every meter length or less of steel reinforcement and left permanently in the structure. However, it has been shown that the interface between spacer and concrete is highly porous and microcracked. This lowers the resistance of the concrete cover to the ingress of aggressive agents causing degradation. This study aims to address this problem by improving spacer design to enhance bond strength and durability of the spacer-concrete interface. Cementitious spacers with a range of surface textures were produced prior to casting into concrete. Samples were prepared with CEM I Portland cement at a water/cement (w/c) ratio of 0.4 and cured for 1, 7, and 28 days in a fog room and then conditioned at 50°C to equilibrium moisture content. The spacer-concrete interface was then tested for tensile bond strength and mass transport properties including oxygen diffusivity, oxygen permeability, and water absorption. The measured surface properties were correlated to the measured bond strength and transport properties to establish the effects of surface texture on the spacer-concrete interface.
AB - Spacers are important devices in reinforced concrete that are used to support reinforcing steel during concreting in order to achieve the required concrete cover. They are placed at every meter length or less of steel reinforcement and left permanently in the structure. However, it has been shown that the interface between spacer and concrete is highly porous and microcracked. This lowers the resistance of the concrete cover to the ingress of aggressive agents causing degradation. This study aims to address this problem by improving spacer design to enhance bond strength and durability of the spacer-concrete interface. Cementitious spacers with a range of surface textures were produced prior to casting into concrete. Samples were prepared with CEM I Portland cement at a water/cement (w/c) ratio of 0.4 and cured for 1, 7, and 28 days in a fog room and then conditioned at 50°C to equilibrium moisture content. The spacer-concrete interface was then tested for tensile bond strength and mass transport properties including oxygen diffusivity, oxygen permeability, and water absorption. The measured surface properties were correlated to the measured bond strength and transport properties to establish the effects of surface texture on the spacer-concrete interface.
KW - Durability
KW - Interface bond strength
KW - Reinforcement spacer
KW - Spacer-concrete interface
KW - Surface texture
KW - Transport properties
UR - http://www.scopus.com/inward/record.url?scp=85079088506&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85079088506
T3 - 6th International Conference on Durability of Concrete Structures, ICDCS 2018
SP - 669
EP - 675
BT - 6th International Conference on Durability of Concrete Structures, ICDCS 2018
A2 - Basheer, P. A. Muhammed
PB - Whittles Publishing Limited
T2 - 6th International Conference on Durability of Concrete Structures, ICDCS 2018
Y2 - 18 July 2018 through 20 July 2018
ER -