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.

International Concrete Abstracts Portal

Showing 1-5 of 97 Abstracts search results

Document: 

20-210

Date: 

May 1, 2021

Publication:

Materials Journal

Volume:

118

Issue:

3


Document: 

19-455

Date: 

March 1, 2021

Author(s):

Mohamed M. Sadek and Assem A. A. Hassan

Publication:

Materials Journal

Volume:

118

Issue:

2

Abstract:

This study evaluated the abrasion resistance for a number of lightweight self-consolidating concrete (LWSCC) incorporating coarse and fine lightweight expanded slate aggregates (LC or LF, respectively). The study also investigated the abrasion resistance before and after exposure to freezing-and-thawing cycles in the presence of deicing salt. The investigated parameters included different volumes of LC and LF aggregates, three binder contents (500, 550, and 600 kg/m3 [31.2, 34.3, and 37.5 lb/ft3]), and different types of concrete (LWSCC, lightweight vibrated concrete, and normal-weight self-consolidating concrete). Increasing the percentage of expanded slate aggregate decreased the abrasion resistance. Mixtures with LF showed higher strength-per-weight ratio and higher abrasion and salt-scaling resistance compared to mixtures with LC. Samples exposed to abrasion before salt scaling had higher mass losses due to salt scaling with an average of 26.8% compared to non-abraded ones. Higher mass loss was also observed in mixtures exposed to abrasion after the exposure to salt scaling with an average of 26% and 43.3% in the rotating-cutter and sandblasting abrasion tests, respectively.

DOI:

10.14359/51729325


Document: 

19-372

Date: 

January 1, 2021

Author(s):

Guilherme S. Araujo, Lui C. Iwamoto, Rosa C. C. Lintz, and Luisa A. Gachet

Publication:

Materials Journal

Volume:

118

Issue:

1

Abstract:

For the production of this lightweight concrete, expanded polystyrene (EPS) associated with expanded clay sintered lightweight aggregates were used to replace nature aggregates. Materials characterization tests were performed, as well as tests of the concrete in the fresh and hardened state. It is worth noting that the fresh tests displayed that the EPS concretes produced met the requirements of ABNT NBR 15823-1: 2017, classifying them as self-compacting. The hardened concrete tests observed the compressive strength, tensile strength, water absorption, void index, and specific mass. All concretes achieved resistances above 20 MPa, considered structural, and presented low specific mass, below 2000 kg/m3, classifying them as light concrete. Scanning electron microscopy (SEM) images allowed a better understanding of the microstructure, justifying the mechanical results obtained. The transition zone between the cement paste and the light aggregates, the number of voids in the cement paste, and the appearance of microcracks were considered.

DOI:

10.14359/51728280


Document: 

19-312

Date: 

September 1, 2020

Author(s):

Ahmed T. Omar, Mohamed M. Sadek, and Assem A. A. Hassan

Publication:

Materials Journal

Volume:

117

Issue:

5

Abstract:

This study aims to evaluate the impact resistance and mechanical properties of a number of developed lightweight self-consolidating concrete (LWSCC) mixtures under cold temperatures. To achieve LWSCC mixtures with minimum possible density, the authors explored different replacement levels of normalweight fine or coarse aggregates by lightweight fine and coarse expanded slate aggregates. The studied parameters included testing temperature (+20°C, 0°C, and –20°C), type of lightweight aggregate (either fine or coarse expanded slate aggregates), binder content (550 and 600 kg/m3 [34.3 and 37.5 lb/ft3]), coarse-to-fine (C/F) aggregate ratio (0.7 and 1.0), and the use of polyvinyl alcohol (PVA) fibers (fibered and nonfibered mixtures). The results indicated that for all tested mixtures, decreasing the temperature of concrete below room temperature significantly improved the mechanical properties and impact resistance. Increasing the percentage of lightweight fine or coarse aggregate in the mixture showed more improvement in the mechanical properties and impact resistance under cold temperatures. However, the failure mode of all tested specimens appeared to be more brittle under subzero temperatures. It was also observed that the inclusion of PVA fibers helped to compensate for the brittleness that resulted from decreasing the temperature, and it further enhanced the impact resistance and mechanical properties under low temperatures.

DOI:

10.14359/51725975


Document: 

19-205

Date: 

May 1, 2020

Author(s):

Rabab Allouzi, Aya Al Qatawna, and Toqa Al-Kasasbeh

Publication:

Materials Journal

Volume:

117

Issue:

3

Abstract:

Foamed concrete is currently studied to investigate its feasibility to be used structurally to produce a lightweight concrete mixture that is workable and has sufficient mechanical properties. This encouraged this research to design a foamed concrete mixture to be used in the construction industry. The main parameters that shall be satisfied for structural use are the workability, density less than 1900 kg/m3, and minimum cylinder compressive strength of 17 MPa (2500 ksi) based on ACI 213R. In this paper, 14 different foamed concrete mixtures are designed and tested to investigate their applicability. As fly ash quality affects foamed concrete permeability and as foamed concrete has low resistance to concentrated stresses, the proposed mixtures do not contain fly ash and are reinforced with polypropylene (PP) fibers. The effect of water-cement ratio (w/c), sand-cement ratio (s/c), PP fibers content, and the foam agent content are investigated. It is found that the compressive strength increases with the increase in density. The optimum s/c is 1:1, w/c is 0.4, and the PP fibers content is 1% by weight of cement. A relationship of splitting tensile strength relative to compressive strength is proposed.

DOI:

10.14359/51722405


12345...>>

Results Per Page 




Please enter this 5 digit unlock code on the web page.