ACI Global Home Middle East Region Portal Western Europe Region Portal
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
Topics In Concrete
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 33 Abstracts search results
Document:
SP154-23
Date:
May 1, 1995
Author(s):
R. A. Miller, B. M. Shahrooz, and A. E. Aktan
Publication:
Symposium Papers
Volume:
154
Abstract:
Examines the relationship between deterioration of concrete and the structural performance of bridge structures. Case 1: A 37-year-old, three-span concrete slab bridge was decommissioned due to heavy deterioration. Modal testing was used to detect the mos
DOI:
10.14359/990
SP154-18
T. Fukute, A. Moriwake, K. Sano, and K. Hamasaki
The Japanese economy has been highly developed through foreign trade. Port facilities have been supporting this economic growth; many concrete port structures have been constructed and maintained during the past few decades. Recently, various social and economical demands have required port facilities to be multi-functional. New facilities are being constructed to meet this trend. These changes include new types of breakwaters, revetment, and undersea tunnels which improve aesthetics and reduce cost, labor, and construction time. Fresh concrete used in the construction of these new types of structures is often required to have high flowability and to be self-compactible because of the complicated shape and densely arranged reinforcements of these structures. To meet these demands, the authors have developed super workable concrete using viscous admixture (segregation-reducing admixture) and super plasticizer. In this paper, the mix design and material properties of this supe rworkable concrete and examples of its application to new port concrete structures are presented.
10.14359/962
SP154-19
N. J. Crammond and M. A. Halliwell
Over the last 50 years, many researchers have investigated the subject of sulfate attack of concrete and special cements have been formulated to combat the problem. However, recent site investigative work and laboratory- based studies carried out by the Building Research Establishment have shown that a particular form of sulfate attack can proceed even in some concretes which were specifically designed to provide good sulfate resistance. In this type of attack, the main mechanism of deterioration is the breakdown of the calcium silicate hydrate phases in the hardened cement paste in the presence of an available supply of sulfate and carbonate ions to produce the mineral thaumasite (CaSiO3CaSO4CaCO315H2O). A microstructural overview incorporating three examples of the thaumasite form of sulfate attack is presented in this paper. The combination of optical and electron microscopy has proved to be a very powerful technique for examining the processes of deterioration in carefully selected site samples
10.14359/963
SP154-24
Y. Fu, J. Ding, and J. J. Beaudoin
Mechanisms of stratlingite (C 2ASH 8) formation in high-alumina cement (HAC)-siliceous material systems were investigated. Different siliceous materials (silica fume, fly ash, ground granulated blast furnace slag) and chemical admixtures (sodium silicate, sodium sulfate) were employed. Reactions between CAH 10 or C 2AH 8 and dissolved silica occur. Acceleration of silica dissolution by addition of chemical admixtures promotes the formation of stratlingite. The pH value of the HAC-siliceous materials system was also studied. The intrinsic relationship between the pH value and stratlingite formation is discussed in this paper. Mechanisms of stratlingite formation in preference to hydrogarnet (C 3AH 6) in HAC products are postulated. A method for prevention of strength reduction of HAC products due to the conversion of thermodynamically unstable hexagonal calcium aluminates to cubic hydrogarnet is described.
10.14359/964
SP154-25
C. Wang and W. H. Dilger
As a result of the very low water-cement ratio in a high-performance concrete, the rate of cement hydration at early ages is significantly different from that in a normal strength concrete. The ultimate degree of cement hydration is lower in a high-performance concrete; the hydration process will terminate earlier because of the rapidly diminishing water supply. Another characteristic of high-performance concrete is caused by the relatively high dosage of superplasticizer which delays the onset of the cement hydration. This paper presents the extension of the research on temperature and strength development in hardening concrete from normal strength concrete to high- performance concrete. It models the development of heat of hydration in high-performance concrete, taking into account the effects of water-cement ratio, superplasticizers, and temperature changes. General formulations of the rate of heat of hydration as functions of concrete maturity (hydration stage) and current temperature are provided. Comparison with some test results verifies the theoretical model.
10.14359/965
Results Per Page 5 10 15 20 25 50 100
Edit Module Settings to define Page Content Reviewer