Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon Nanotubes

In this study, an experimental program was conducted to investigate the shear behavior of beams made of high-strength and lightweight cementitious composites (HS-LWCCs) containing hollow glass microspheres and carbon nanotubes. The compressive strength and dry density of the HS-LWCCs were 87.8 MPa a...

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Main Authors: Dongmin Lee, Seong-Cheol Lee, Oh-Sung Kwon, Sung-Won Yoo
Format: Article
Language:English
Published: MDPI AG 2024-09-01
Series:Buildings
Subjects:
Online Access:https://www.mdpi.com/2075-5309/14/9/2824
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author Dongmin Lee
Seong-Cheol Lee
Oh-Sung Kwon
Sung-Won Yoo
author_facet Dongmin Lee
Seong-Cheol Lee
Oh-Sung Kwon
Sung-Won Yoo
author_sort Dongmin Lee
collection DOAJ
description In this study, an experimental program was conducted to investigate the shear behavior of beams made of high-strength and lightweight cementitious composites (HS-LWCCs) containing hollow glass microspheres and carbon nanotubes. The compressive strength and dry density of the HS-LWCCs were 87.8 MPa and1.52 t/m<sup>3</sup>, respectively. To investigate their shear behavior, HS-LWCC beams with longitudinal rebars were fabricated. In this test program, the longitudinal and shear reinforcement ratios were considered as the test variables. The HS-LWCC beams were compared with ordinary high-strength concrete (HSC) beams with a compressive strength of 89.3 MPa to determine their differences; the beams had the same reinforcement configuration. The test results indicated that the initial stiffness and shear capacity of the HS-LWCC beams were lower than those of the HSC beams. These results suggested that the low shear resistance of the HS-LWCC beams led to brittle failure. This was attributed to the beams’ low elastic modulus under compression and the absence of a coarse aggregate. Furthermore, the difference in the shear capacity of the HSC and HS-LWCC beams slightly decreased as the shear reinforcement ratio increased. The diagonal compression strut angle and diagonal crack angle of the HS-LWCC beams with shear reinforcement were more inclined than those of the HSC beams. This indicated that the lower shear resistance of the HS-LWCCs could be more effectively compensated for when shear reinforcement is provided and the diagonal crack angle is more inclined. The ultimate shear capacities measured in the tests were compared with various shear design provisions, including those of ACI-318, EC2, and CSA A23.3. This comparison showed that the current shear design provisions considerably overestimate the contribution of concrete to the shear capacity of HS-LWCC beams.
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spelling doaj-art-d3807922e5fb4e01b4f30b61efb9e1cc2025-08-20T01:56:06ZengMDPI AGBuildings2075-53092024-09-01149282410.3390/buildings14092824Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon NanotubesDongmin Lee0Seong-Cheol Lee1Oh-Sung Kwon2Sung-Won Yoo3Department of Civil Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Deagu 41566, Republic of KoreaDepartment of Civil Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Deagu 41566, Republic of KoreaDepartment of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, ON M5S 1A4, CanadaDepartment of Civil and Environmental Engineering, Gachon University, 1342 Seongnamdae-ro, Sujeong-gu, Seongnam-si 13120, Republic of KoreaIn this study, an experimental program was conducted to investigate the shear behavior of beams made of high-strength and lightweight cementitious composites (HS-LWCCs) containing hollow glass microspheres and carbon nanotubes. The compressive strength and dry density of the HS-LWCCs were 87.8 MPa and1.52 t/m<sup>3</sup>, respectively. To investigate their shear behavior, HS-LWCC beams with longitudinal rebars were fabricated. In this test program, the longitudinal and shear reinforcement ratios were considered as the test variables. The HS-LWCC beams were compared with ordinary high-strength concrete (HSC) beams with a compressive strength of 89.3 MPa to determine their differences; the beams had the same reinforcement configuration. The test results indicated that the initial stiffness and shear capacity of the HS-LWCC beams were lower than those of the HSC beams. These results suggested that the low shear resistance of the HS-LWCC beams led to brittle failure. This was attributed to the beams’ low elastic modulus under compression and the absence of a coarse aggregate. Furthermore, the difference in the shear capacity of the HSC and HS-LWCC beams slightly decreased as the shear reinforcement ratio increased. The diagonal compression strut angle and diagonal crack angle of the HS-LWCC beams with shear reinforcement were more inclined than those of the HSC beams. This indicated that the lower shear resistance of the HS-LWCCs could be more effectively compensated for when shear reinforcement is provided and the diagonal crack angle is more inclined. The ultimate shear capacities measured in the tests were compared with various shear design provisions, including those of ACI-318, EC2, and CSA A23.3. This comparison showed that the current shear design provisions considerably overestimate the contribution of concrete to the shear capacity of HS-LWCC beams.https://www.mdpi.com/2075-5309/14/9/2824crack anglehigh-strength concretelightweight concreteshear behaviorshear design
spellingShingle Dongmin Lee
Seong-Cheol Lee
Oh-Sung Kwon
Sung-Won Yoo
Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon Nanotubes
Buildings
crack angle
high-strength concrete
lightweight concrete
shear behavior
shear design
title Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon Nanotubes
title_full Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon Nanotubes
title_fullStr Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon Nanotubes
title_full_unstemmed Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon Nanotubes
title_short Shear Behavior of High-Strength and Lightweight Cementitious Composites Containing Hollow Glass Microspheres and Carbon Nanotubes
title_sort shear behavior of high strength and lightweight cementitious composites containing hollow glass microspheres and carbon nanotubes
topic crack angle
high-strength concrete
lightweight concrete
shear behavior
shear design
url https://www.mdpi.com/2075-5309/14/9/2824
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AT ohsungkwon shearbehaviorofhighstrengthandlightweightcementitiouscompositescontaininghollowglassmicrospheresandcarbonnanotubes
AT sungwonyoo shearbehaviorofhighstrengthandlightweightcementitiouscompositescontaininghollowglassmicrospheresandcarbonnanotubes