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 14 Abstracts search results
Document:
SP249-05
Date:
March 1, 2008
Author(s):
D.A. Abrams
Publication:
Symposium Papers
Volume:
249
Abstract:
A discussion preceding a demonstration of actual field proportioning of concrete by Stanton Walker. Mr. Walker has prepared a resume of the methods used which appears on p. 182 of this volume.
DOI:
10.14359/20126
SP249-12
J.P. Romualdi and G.B. Batson
Due to copyright issues, this paper is only available by purchasing the SP-249. The application of linear-elastic fracture mechanics reveals that the strength of concrete in tension is limited by internal holes and micro-cracks. Fracture arrest can be achieved by reducing the spacing of reinforcement to a suitable scale. Reinforcement diameter decreases in proportion to reduction in spacing in order to maintain steel percentage. Theoretical results indicate that the tensile cracking strength of concrete increases in proportion to the inverse square root of the reinforcement spacing. Tests on closely spaced wire reinforced beams support the theoretical calculations.
Due to copyright issues, this paper is only available by purchasing the SP-249.
10.14359/20133
SP249-11
A. Hillerborg, M. Modeer, and P.E. Petersson
Due to copyright issues, this paper is only available by purchasing the SP-249. A method is presented in which fracture mechanics is introduced into finite element analysis by means of a model where stresses are assumed to act across a crack as long as it is narrowly opened. This assumption may be regarded as a way of expressing the energy absorption Gc in the energy balance approach, but it is also in agreement with results of tension tests. As a demonstration the method has been applied to the bending of an unreinforced beam, which has led to an explanation of the difference between bending strength and tensile strength, and of the variation in bending strength with beam depth.
10.14359/20132
SP249-08
C.A. Menzel
Due to copyright issues, this paper is only available by purchasing the SP-249. Cracks often develop in the surface of fresh concrete soon after it has been placed or finished and while it is still in the plastic state. The development of such cracks, commonly referred to as plastic cracking, can be practically eliminated if appropriate measures to minimize the causes are taken at the right time. The development, location and extent of cracks in fresh concrete may be readily observed if they occur in the exposed top surface. However, cracks may also develop, though much less frequently, in the vertical surface of fresh concrete slabs in horizontal forms. Cracks in vertical surfaces are seldom due to drying shrinkage, which is the most frequent cause of top-surface cracks.
10.14359/20129
SP249-07
T.C. Powers and R.A. Helmuth
Due to copyright issues, this paper is only available by purchasing the SP-249. New experimental data are presented on the freezing of hardened portland-cement pastes with and without entrained air. They are explained in terms of two mechanisims: 1) the generation of hydraulic pressure as water freezes in capillary cavities and 2) the growth of the bodies of ice in the capillary cavities or air voids by diffusion of water from the gel. Air voids limit the hydraulic pressure and shorten the period during which the ice in the cavities can increase. The closer the air voids are to each other the more effective they are in controlling either mechanism.
10.14359/20128
Results Per Page 5 10 15 20 25 50 100