Email Address is required Invalid Email Address
In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Learn More
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
Staff Directory
ACI World Headquarters 38800 Country Club Dr. Farmington Hills, MI 48331-3439 USA Phone: 1.248.848.3800 Fax: 1.248.848.3701
ACI Middle East Regional Office Second Floor, Office #207 The Offices 2 Building, One Central Dubai World Trade Center Complex Dubai, UAE Phone: +971.4.516.3208 & 3209
ACI Resource Center Southern California Midwest Mid Atlantic
Feedback via Email Phone: 1.248.848.3800
Home > Publications > 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.
Showing 1-5 of 436 Abstracts search results
Document:
23-152
Date:
April 1, 2024
Author(s):
Ronald Lichtenwalner and Joseph T. Taylor
Publication:
Materials Journal
Volume:
121
Issue:
2
Abstract:
This experimental study evaluated the correlation between measured concrete expansion from a modified version of the miniature concrete prism test (MCPT) with the concentration of chemical markers leached from the prisms into an alkaline soak solution. Fifteen concrete mixture designs were tested for expansion and soak solution concentrations over time. The changes in expansion and soak solution concentrations were found to correlate well even with variations in alkali loading and substitution of cement with Class F fly ash. A model was developed to estimate the expansion potential of concrete based on an expansion reactivity index (ERI) that incorporated the concentrations of silicon, sulfate, calcium, and aluminum. The relationship between ERI and expansion was then used to identify potentially expansive concrete mixtures using the ERI of cores taken from a structure exhibiting potential alkalisilica reaction (ASR) expansion and concrete cylinders matching the mixture designs of the MCPT specimens.
DOI:
10.14359/51740374
22-286
K. Sriram Kompella, Andrea Marcucci, Francesco Lo Monte, Marinella Levi, and Liberato Ferrara
The early-age material parameters of three-dimensional (3-D)-printable concrete defined under the umbrella of printability, namely, pumpability, extrudability, buildability, and the “printability window/open time,” are subjective measures. The need to correlate and successively substitute these subjective measures with objective and accepted material properties, such as tensile strength, shear strength, and compressive strength, is paramount. This study validates new testing methodologies to quantify the tensile and shear strengths of printable fiber-reinforced concretes still in their fresh state. A tailored mixture with high sulfoaluminate cement and nonstructural basalt fibers has been assumed as a reference. The relation between the previously mentioned parameters and rheological parameters, such as yield strength obtained through International Center for Aggregates Research (ICAR) rheometer tests, is also explored. Furthermore, in an attempt to pave the way and contribute toward a better understanding of the mechanical properties of 3-D-printed concrete, to be further transferred into design procedures, a comparative study analyzing the work of fracture per unit crack width in three-point bending has been performed on printed and companion nominally identical monolithically cast specimens, investigating the effects of printing directions, position in the printed circuit, and specimen slenderness (length to depth) ratio.
10.14359/51740302
22-424
C. Pleesudjai, D. Patel, K. A. Williams Gaona, M. Bakhshi, V. Nasri, and B. Mobasher
Statistical process control (SPC) procedures are proposed to improve the production efficiency of precast concrete tunnel segments. Quality control test results of more than 1000 ASTM C1609/C1609M beam specimens were analyzed. These specimens were collected over 18 months from the fiber-reinforced concrete (FRC) used for the production of precast tunnel segments of a major wastewater tunnel project in the Northeast United States. The Anderson-Darling (AD) test for the overall distribution indicated that the data are best described by a normal distribution. The initial residual strength parameter for the FRC mixture, f D 600, is the most representative parameter of the post-crack region. The lower 95% confidence interval (CI) values for 28-day flexural strength parameters of f1, f D 600, and f D 300 exceeded the design strengths and hence validated the strength acceptability criteria set at 3.7 MPa (540 psi). A combination of run chart, exponentially weighted moving average (EWMA), and cumulative sum (CUSUM) control charts successfully identified the out-of-control mean values of flexural strengths. These methods identify the periods corresponding to incapable manufacturing processes that should be investigated to move the processes back into control. This approach successfully identified the capable or incapable processes. The study also included the Bootstrap Method to analyze standard error in the test data and its reliability to determine the sample size.
10.14359/51740373
23-010
January 1, 2024
Sahith Gali and Sri Sritharan
1
Ultra-high-performance concrete (UHPC) is a cementitious concrete material known for its sustained post-cracking tensile performance. Various specimen geometries and different test approaches have been used to establish the tensile characteristics of UHPC. Intending to standardize a direct tension test method, this paper independently evaluates a procedure developed by the Federal Highway Administration (FHWA), which has been adopted into AASHTO T 397. To verify the reliability and repeatability of the test method, 216 tensile specimens were cast from three different UHPC types with fiber-volume fractions of 1, 2, and 3% and tested at six laboratories. The measured responses were characterized for different phases of the tensile behavior and analyzed to understand the scatter in the test data. It was found that testing can be executed with a 60 to 70% success rate with carefully prepared samples and some modifications to the proposed test method. The test results show an increase in both the tensile strength and multicracking phase with an increase in fiber-volume fraction, but the crack straining phase depends primarily on the type of UHPC. Using the test data, average and characteristic tensile responses were established, which are intended, respectively, for analysis and design purposes.
10.14359/51739204
23-001
Hak-Young Kim, Keun-Hyeok Yang, Hye-Jin Lee, Seung-Jun Kwon, and Xiao-Yong Wang
The objective of the present study is to assess the flexural residual strengths of lightweight aggregate concrete (LWAC) reinforced with micro-steel fibers. Further, the material class of such concrete was examined through comparison with the fiber-reinforced concrete classification specified in the provisions of fib 2010. Fourteen beam specimens were classified into L (21 MPa [3.05 ksi]) and H (40 MPa [5.80 ksi]) groups according to the design compressive strength of LWAC. The volume fraction of micro-steel fibers varied from 0 to 1.5% at a spacing of 0.25% in each beam group. From the beam test results under the three-point loading condition, flexural stress-crack mouth opening displacement (CMOD) curves were measured and then discussed as a function of the fiber reinforcing index (βf). The flexural residual strengths corresponding to four different CMOD values (0.5, 1.5, 2.5, and 3.5 mm [0.02, 0.06, 0.1, and 0.14 in.]) were compared with previous empirical equations and fib 2010 classification. The various analyses of the measured results indicate that βf can be regarded as a critical factor in directly determining the magnitude of flexural residual strengths and assessing material classification. The proposed refined equations improve the accuracy in predicting the flexural residual strengths of concrete beams with different densities and reinforced with different types of steel fibers. Consequently, microsteel fibers are a promising partial replacement for conventional steel reinforcing bars to enhance the ductility of LWAC elements.
10.14359/51739203
Results Per Page 5 10 15 20 25 50 100