Natural Aggregates in Structural Lightweight Concrete
Pumice and scoria have been used in structural concrete since the days of the Roman Empire. Records for the past five decades show minimal use of these materials in structural concrete...
Polymer Concretes
Polymer Concrete (PC) is prepared by using polymeric materials to bond inert aggregates in a fashion similar to that of Portland Cement in the preparation of Portland Cement Concrete (PCC)....
Concrete Lunar Bases
Scientific and industrial operations on the moon require suitably shielded structures. Small structures for limited scientific activities may be constructed from structural elements prefabricated...
Fast Track Paving May Offer Applications to Structures
'Fast Track' is a technique that permits portland cement concrete pavements to be opened to traffic in a day or less after they are poured. The method has been...
Recent Development of Cement-Based Materials
Development of advanced techniques has enhanced the capability of more accurate characterization of engineering materials at both the microscopic and macroscopic levels. Through better...
Microsilica (Silica Fume) Concrete Durability in Severe Environments
Microsilica (silica fume) concrete has provided increased durability in a variety of aggressive environments. Technical information is presented for microsilica concretes exposed to fire,...
Chloride Diffusion Constant for Concretes
Reinforced concrete exposed to chloride ions rapidly deteriorates once the chloride concentration level exceeds the corrosion threshold limit. The diffusion of the chloride ion through...
Testing of Reinforced Concrete Bridges for External Reinforcement
Several continuous reinforced concrete slab bridges were constructed in the 1950's with spans ranging from 30 ft. to 60 ft. Longitudinal cracks were observed in the tension...
Sulfate Attack on Concrete Containing Fly Ash
The use of fly ash as a portland cement replacement in concrete may provide many technical and economic advantages. One such technical advantage is to improve the resistance of concrete...
Freezing and Thawing Durability of High Strength Silica Fume Concrete
Specimens from 27 batches of concrete with a water to cementitious (cement plus silica fume) ratio of 0.25 to 0.32, with and without entrained air, were tested for freeze-thaw durability...
Fatigue and Fracture Evaluation of Riveted Bridge Members
Among the major concerns of bridge engineers today are the fatigue damages that have been accumulated in riveted members and the safety of riveted structures. Many of these structures...
Fatigue Strength of Corroded Rolled Beams
Highway and railway bridges fabricated from ASTM A7, A36, and A572 steels will corrode if the paint system is allowed to fail for lack of maintenance. Corroding members lose cross section...
A Method of Computing Impact and Fatigue Life in the Railway Steel Girder Bridge
The purpose of this paper is to investigate the dynamic interactions between an steel girder bridge and a moving freight train. A non-linear, 100-ton, freight car vehicle model and a 70-ft...
Fatigue Evaluation of a Riveted Railroad Bridge
An 83 year old railroad bridge was analyzed for fatigue based on historical records such as the original schedules. Based on the number of cycles to date, corresponding to an effective...
Service Life of Underground Concrete Structures
The service life of underground concrete depends on both the physicochemical properties of the concrete materials and the properties of the in-service environment. The major factors controlling...
Fiberglas Reinforced Plastic Rebars in Lieu of Steel Rebars
Fiberglass reinforced plastics have recently been introduced in the market in the form of rebars for concrete reinforcement. The light weight, corrosion resistance and non-magnetic properties...
Enhancing Concrete Durability by Treatment with Sealers
This paper summarizes some of the research which has been undertaken on sealers for hardened concrete during the last ten years at Wiss, Janney, Elstner Associates. Inc. The research used...
Surface Treatments for Concrete
The US Army Corps of Engineers initiated in 1984 a research program designated Repair, Evaluation, Maintenance, and Rehabilitation (REMR), one of the work units being the evaluation of...
The Use of Penetrating Sealers on Concrete Bridge Decks
Acceptance criteria for Penetrating sealers is shown. Penetrating sealers can be used as cost effective preventive maintenance for bridge deck concrete in northern climates. Factors affecting...
Evaluation and Remediation of Construction Defects in Tilt Wall Panels
Both the surface appearance and structural safety were of concern to the Owner of a five year old warehouse structure that was experiencing delamination of tilt-up wall panels. Delamination...
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