International Concrete Abstracts Portal

Showing 1-5 of 22 Abstracts search results

Document: 

22-104

Date: 

May 1, 2023

Author(s):

Wen-Cheng Shen and Shyh-Jiann Hwang

Publication:

Structural Journal

Volume:

120

Issue:

3

Abstract:

The use of high-strength concrete (HSC) in high-rise buildingscan reduce the size of structural members and increase the residential space. However, the behavior of HSC at ultimate loads is more brittle than that of normal-strength concrete. Hence, the ACI 318-19 building code requires that all the column longitudinal bars be confined by seismic hooks when using HSC (fc′ > 70 MPa [10.15 ksi]) or under high axial loads (Pu > 0.3Agfc′). The requirement for crossties with seismic hooks at both ends might cause a huge impact on the assemblage of the column reinforcement cage during field installation. This research proposes an experimental study of full-scale column specimens with a 600 x 600 mm (23.62 x23.62 in.) cross-sectional dimension subjected to quasi-staticcyclic loading under constant high axial load. These column specimens are composed of both HSC and high-strength reinforcement. Test results show that if crossties with a 90-degree hook at one end are alternated, the column specimen maintains satisfactory seismic performance. This change in detailing can facilitate the field installation of the reinforcement cage for columns using HSC or underhigh axial loads.

DOI:

10.14359/51738505


Document: 

20-437

Date: 

September 1, 2021

Author(s):

Ren-Jie Tsai, Yu-Cheng Hsu, and Shyh-Jiann Hwang

Publication:

Structural Journal

Volume:

118

Issue:

5

Abstract:

Many residential buildings in Taiwan use reinforced concrete (RC) walls with openings; the stiffness and strength of the walls with openings greatly influence the structural seismic behaviors. Neglecting the lateral capacities of these RC walls with openings may cause mispredictions of seismic evaluation and may lose the economy of seismic retrofitting to low-rise buildings. To address this concern, this paper presents a prediction model of the lateral load-displacement curve of RC walls with openings in shear failure on the basis of the force-transfer mechanism. This model is applicable for cases where the openings create weak areas in the vertical wall segments. Test specimens of squat walls with aspect ratios less than 0.82 and a window opening at the center are selected for verification. A comparison of the skeleton curves from the prediction and experiments indicates that this model is reasonable and can be applied as an analytical model for practical use.

DOI:

10.14359/51732835


Document: 

18-524

Date: 

January 1, 2020

Author(s):

Dipayan Jana

Publication:

Materials Journal

Volume:

117

Issue:

1

Abstract:

Extensive cracking in thousands of residential concrete foundations in eastern Connecticut is found to be due to two-stage expansions associated with oxidation of pyrrhotite in crushed gneiss coarse aggregate of concrete used from a local quarry that sits on a hydrothermal vein of significant pyrrhotite crystallization, followed by internal sulfate attack in concrete from the sulfates released by pyrrhotite oxidation. Microstructural, chemical, and mineralogical evidences of pyrrhotite oxidation and the resultant internal sulfate attack in concrete are presented from a case study. A five-step laboratory testing protocol is suggested for assessment of aggregates from the area to prevent pyrrhotite-related deterioration for future construction.

DOI:

10.14359/51718059


Document: 

17-391

Date: 

September 1, 2018

Author(s):

Rou-Ling Yeh, Chien-Chuang Tseng, and Shyh-Jiann Hwang

Publication:

Structural Journal

Volume:

115

Issue:

5

Abstract:

To provide practical functions, reinforced concrete (RC) walls in residential buildings often have door or window openings that divide the RC wall into different segments. This study conducted experiments on four RC wall specimens with openings. By observing the crack development within the specimen, the effect of special horizontal reinforcement on the shear strength of vertical wall segments is assessed. Experimental observations show that placing special horizontal shear reinforcement or carbon fiber tapes above and below vertical wall segments at the edges of walls can satisfy nodal force balance at these locations and effectively increase the shear strength of these vertical wall segments. In addition to reporting the experimental results, this study compares the shear strength obtained from experiments and that computed based on the ACI 318-14 Building Code, and proposes an appropriate strut-and-tie model for predicting the shear strength.

DOI:

10.14359/51702377


Document: 

15-265

Date: 

March 1, 2017

Author(s):

M. C. Caruso, C. Menna, D. Asprone, A. Prota, and G. Manfredi

Publication:

Structural Journal

Volume:

114

Issue:

2

Abstract:

This study aims to define a methodological framework that could guide construction community stakeholders in conducting environmental sustainability comparisons among building systems at the design stage. The study proceeds on the basis that the design of new structures starts with specific requirements, including national technical standards. An application of the proposed framework for the comparative life-cycle assessment (LCA) concerning a residential building is presented; three different structural materials are compared—namely, reinforced concrete (RC), steel, and wood. Starting with functional, architectural, and structural requirements, the building is designed and verified to take into account how structural solutions change depending on each building material. A cradle-to-grave LCA study is conducted for the three alternative structures using SimaPro software; both IMPACT2002+ and EPD2008 methodologies are used to quantify environmental impacts.

DOI:

10.14359/51689426


12345

Results Per Page 





ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.