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:
SP109-21
Date:
August 1, 1988
Author(s):
S. Nishibayashi, S. Hideshima, S. Negami, and M. Takada
Publication:
Symposium Papers
Volume:
109
Abstract:
Effect of chemical and mineral admixtures on the durability of concrete in an undersea environment has been studied. Addition of slag and slag-like materials and water-reducing agent improves the durability of concrete. However, alkali-silica aggregate reaction aggravated by the marine environment and the corrosion of reinforcing steel bars are enhanced. By the addition of rust inhibitors, these effects can be controlled.
DOI:
10.14359/2025
SP109-22
A. K. Haug and M. Sandvik
To meet the development in structural design and construction methods, a continuous effort has been made to advance the concrete mix design process. Paper gives a survey of the research work in this process. The mix design has to take care of several contradictory requirements, such as high strength and low permeability on one side and moderate heat development and extraordinary workability on the other. From 1972 to 1986, the concrete grade has been increased from C45 to C70 while the workability (slump) has been increased from 120 to 240 mm mainly due to extreme dense reinforcement (above 1000 kg/m3 in local areas). The chemical composition of the cement is aimed at an optimized 28 day compressive strength with moderate heat development. The fine aggregates are produced through a hydraulic process to obtain the desired particle distribution. Minor changes in the finer part of the grading have resulted in remarkable improvements in the workability and pumpability by stabilizing the paste-aggregate matrix. The practical use of very high strength normal density concrete (C80-C100) and high-strength concrete with lightweight aggregates are new challenges for the concrete mix design so as to satisfy new advancements in construction methods.
10.14359/2037
SP109-31
A. J. Hulshizer and A. Kodal
The ocean-cooling water supply and return system for the Seabrook Nuclear Power Plant is a vital link in the operation of the multibillion dollar facility. The water conveyance system is comprised of three main concrete construction components, each representing different construction techniques and somewhat different corrosion problems and approaches to promoting durability. Concrete intake heads, weighing 227 tons each, were precast off site and utilized nickel-coated reinforcement as a special means to preclude corrosion which otherwise would be accelerated by the presence of a 90-10 copper-nickel anti-fouling cladding. Prefabricated 1.52 and 2.87 m diameter vertical ocean shafts have their steel outer casings protected against corrosion by a mesh reinforced, spin cast, low water-cement ratio, mortar lining. Over 10 km of 5.8 meter diameter tunnels and the vertical land shafts were constructed of conventional cast-in-place, reinforced concrete. The subsea location of the structures and the depth of the tunnels demand that the concrete perform virtually maintenance free for the 40 year design life of the plant. Paper discusses the initial design considerations, construction experiences, and observations from the underwater inspection conducted on the various concrete components, after having been submerged for as much as 7 years at the time of inspection.
10.14359/3570
SP109-19
G. C. Hoff
The mechanism by which ice floes occurring in rivers, lakes, and oceans can damage concrete structures in the water is hypothesized. Various test methods to evaluate the effects of ice abrasion and impact on concrete are reviewed, and selected results using these methods are presented. Several field studies of the effects of ice abrasion on concrete structures are identified.
10.14359/3576
SP109-05
J. V. Sharp, J. W. Figg, and M. B. Leeming
Several projects in the "Concrete in the Oceans" program have measured electrical potentials and resistivities on reinforced concrete specimens exposed to a marine environment. A state of the art survey was also undertaken on corrosion monitoring techniques which led to experimental work to improve the use of these techniques, particularly on marine structures. The main conclusions from this test program are discussed. Two independent sets of electropotential and resistivity measurements taken on beam specimens exposed to a splash zone environment for periods up to five years have been compared with the actual corrosion found after the reinforcement was broken out of the specimens. The comparison of these two sets of data and the ability of these monitoring techniques to predict likely corrosion are discussed and related to the various parameters such as the disposition of the cracks, the depth of cover and the type of concrete. Based on the work described in this paper, the limitations of corrosion monitoring methods are also highlighted.
10.14359/1940
Results Per Page 5 10 15 20 25 50 100
Edit Module Settings to define Page Content Reviewer