International Concrete Abstracts Portal

Showing 1-5 of 321 Abstracts search results

Document: 

23-257

Date: 

August 1, 2024

Author(s):

Leigh E. W. Ayers and Isaac L. Howard

Publication:

Materials Journal

Volume:

121

Issue:

4

Abstract:

In this paper, several hundred specimens were compacted and tested to evaluate the potential of beam testing protocols to directly measure four mechanical properties from one beam. Mechanical properties measured through beam testing protocols were compared to properties of plastic mold (PM) device specimens and were found to be comparable once specimen densities were corrected. Mechanical properties were also used to quantify mechanical property relationships, often used as pavement design inputs. When compared to traditionally recommended mechanical property relationships, relationships between elastic modulus and unconfined compressive strength, as well as modulus of rupture and unconfined compressive strength, were overly conservative; however, indirect tensile strength and unconfined compressive strength relationships from the literature were accurate. This paper also assessed an elevated-temperature curing protocol to simulate later-life pavement mechanical properties on laboratory specimens. Mechanical properties of laboratory specimens that underwent accelerated curing were shown to be comparable to 10- to 54-year-old cores taken from Mississippi highways.

DOI:

10.14359/51740780


Document: 

23-055

Date: 

May 1, 2024

Author(s):

Sangyoung Han, Thanachart Subgranon, Hung-Wen Chung, Kukjoo Kim, and Mang Tia

Publication:

Materials Journal

Volume:

121

Issue:

3

Abstract:

A comprehensive laboratory testing program, field-testing program, numerical analysis, and life-cycle cost analysis were conducted to evaluate the beneficial effects of incorporating shrinkage-reducing admixture (SRA), polymeric microfibers (PMFs), and optimized aggregate gradation (OAG) into internally cured concrete (ICC) mixtures for rigid pavement applications. Results from the laboratory program indicate that all the ICC mixtures outperformed the standard concrete (SC) mixture. All the ICC mixtures showed a decrease in drying shrinkage compared to the SC mixture. Based on the laboratory program, three ICC mixtures and one SC mixture were selected for the full-scale test and subjected to a heavy vehicle simulator for accelerated fatigue testing. Extensive testing and analysis have shown that ICC mixtures incorporating SRA, PMFs, and OAG can be beneficially used in pavement applications to achieve increased pavement life.

DOI:

10.14359/51740564


Document: 

21-381

Date: 

December 1, 2023

Author(s):

Othman AlShareedah and Somayeh Nassiri

Publication:

Materials Journal

Volume:

120

Issue:

6

Abstract:

Pervious concrete is a stormwater management practice used in the United States, Europe, China, Japan, and many other countries. Yet the design of pervious concrete mixtures to balance strength and permeability requires more research. Sphere packing models of pervious concrete were used in compressive strength testing simulations using the discrete element method with a cohesive contact law. First, three mixtures with varied water-cement ratios (w/c) and porosities were used for model development and validation. Next, an extensive database of simulated compressive strength and tested permeability was created, including 21 porosities at three w/c. Analysis of the database showed that for pavement applications where high permeability and strength are required, the advised porosity is 0.26 to 0.30, producing average strengths of 14.4, 11.1, and 7.7 MPa for w/c of 0.25, 0.30, and 0.35. The model can guide the mixture design to meet target performance metrics, save materials and maintenance costs, and extend the pavement life.

DOI:

10.14359/51739157


Document: 

22-177

Date: 

November 1, 2023

Author(s):

Nathanial Buettner and Julie Vandenbossche

Publication:

Structural Journal

Volume:

120

Issue:

6

Abstract:

Superloads, defined as vehicles with a gross vehicle weight of over 890 kN, are believed to overload jointed plain concrete pavements (JPCPs) and have the potential to cause significantly more fatigue damage than typical truck traffic. It is anticipated that the fatigue damage is greater when the superload is applied later in the life of the JPCP. In this study, the stress pulses generated by superloads on JPCPs were characterized using finite element modeling and related to fatigue damage through the fatigue testing of concrete beams. Concrete beams subjected to loading profiles that simulate those of a superload were observed to accumulate fatigue damage at an accelerated rate when applied after 70% of the fatigue life of the concrete was consumed. Moreover, through the collection of fatigue life and beam response data, the effects of stress ratio, stress range, flexural strength, and damage state at the time of loading on the fatigue damage imposed by a superload movement were elucidated.

DOI:

10.14359/51739086


Document: 

21-493

Date: 

January 1, 2023

Author(s):

M. Selvam and Surender Singh

Publication:

Materials Journal

Volume:

120

Issue:

1

Abstract:

Lack of understanding of the compaction mechanism, both in the laboratory and field, could result in significant underestimation or overestimation of the roller-compacted concrete pavement (RCCP) performance. The literature (1987 to 2022) depicts that there are numerous techniques to design RCCP in the laboratory; however, which method could closely simulate the field compaction is not fully explored. The present paper critically reviews the fundamental parameters affecting the strength characteristics of RCCP when compacted with different compaction mechanisms in the laboratory and attempts to rank the compaction methods based on the field performance. Also, recommendations are made on how to fabricate the specimens without having much impact on the considered compaction technique. The techniques that have been considered are the vibratory hammer, vibratory table, modified Proctor, gyratory compactor, and special compactors such as California kneading compactor, Marshall hammer, and duplex roller. Based on the present review, future research prospects are outlined to improve the performance of RCCP.

DOI:

10.14359/51737290


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