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 63 Abstracts search results
Document:
SP193-31
Date:
August 1, 2000
Author(s):
M. Imam and L. Vandewalle
Publication:
Symposium Papers
Volume:
193
Abstract:
The paper investigates the shear strength and the failure modes of high strength concrete beams with and without steel fibers ( fC = 110 MPa). Sixteen reinforced high strength concrete beams (3600x350~200 mm) were tested under different combinations of shear force and bending moment. The beams were singly reinforced and without shear (web) reinforcement. The test results indicated that the addition of steel fibers to high strength concrete increases the ultimate shear strength, improves the brittle characteristic and transforms the failure mode into a more ductile one. The average gain of the ultimate shear strength due to the addition of steel fibers varied from about 14% to 14 1% depending on the shear span to depth ratio and the longitudinal steel ratio. Four modes of failure of reinforced high strength concrete are clearly distinguished as; diagonal tension, shear compression, shear flexure, and flexural failure. In general, cracks in fiber reinforced concrete beams are closer, narrower, and more than those in beams without fibers. This reflects the effect of steel fibers in redistributing the stresses beyond cracking.
DOI:
10.14359/5841
SP193
Editor: V.M. Malhotra
In September 2000, the American Concrete Institute sponsored the ACI Fourth International Conference in Seoul, Korea. Sixty-two papers are included in this publication. Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP193
10.14359/14227
SP193-01
N. J. Carino and K. W. Meeks
This paper reports the results of an exploratory study on the effects of curing duration on the variation of mortar strength with distance from the drying surface. A novel, notched cylindrical test specimen was adopted for measuring tensile strength at different depths. Two mortar mixtures with w/c of 0.30 and 0.45 were used; the former was assumed to be representative of the paste system in a high-performance concrete. Specimens were moist cured for (1, 3, or 7) d and then exposed to air at 25 “C and 50 % or 70 % RH. The cylinders were sealed to simulate one-dimensional drying in a large member. Tensile strengths were measured at 28 d. Relationships between tensile strength and depth were compared with those of specimens continuously moist cured. The data tended to show that 1 d of moist curing might be sufficient to ensure adequate strength development at a depth of 25 mm from the exposed surface. The phenomenon of increasing strength with drying may have confounded the results, and recommendations for additional studies are provided.
10.14359/5811
SP193-02
K. G. Bottger and D. Knofel
This contribution deals with the development of slurries for the restoration of brickwork buildings in Northern Germany. Various slurries on the basis of two binders with a high sulphate resistance with an admixture of solid glass globules respectively were developed, one slurry on the basis of lime the other on the basis of cement. Their aggregate is of fine quartz sands and various additives were used. The slurries were developed to restore historical terracotta. Beside the workability and the water retention capacity of the slurries, technological pa-rameters such as dynamic modulus of elasticity, compressive strength, bending and bond strength and hygrical parameters such as water absorption, water desorptions and water vapour diffusion were investigated. Further important characteristics were the resistance to freezing and thawing, the scuff resistance and the efflorescence behaviour. Some of the slurries were successfully applied to the terracotta surfaces.
10.14359/5812
SP193-03
A. P.-C. Sze and C. T.-W. Chan
The Hong Kong Mass Transit Railway Corporation, carrying a daily patronage of over 2 million, has a prime objective of providing a safe and reliable railway transportation system to the public in Hong Kong. The existing Urban Line System is situated mostly underground through soft, marine deposits and/or rock. The aggressive underground conditions in the coastal regions had resulted in various degrees of deterioration to the tunnel linings in a period less than 10 years from completion. The problem was most serious where precast concrete (PCC) lining was adopted because of the existence of segmental joints. A special method of repair was jointly developed by MTRC and Skanska International Civil Engineering AB. A robotic high pressure water jet system (hydrodemolition) is used to remove the surface delaminated concrete, and the surface repaired with a 75 mm layer of low permeability, fibre (polypropylene) reinforced shotcrete. Repair has to be implemented in the short time window during non traffic-hours each night with absolutely no disruption to the daily traffic.
10.14359/5813
Results Per Page 5 10 15 20 25 50 100
Edit Module Settings to define Page Content Reviewer