The prime objective of this programme is to develop an ac-zelerated freeze/thaw performance test that relates reliably tofield performance.Samples of 40 experimental block mixes have been placed onone or more of 5 exposure sites. Data from meteorologicalstations on these sites are being used to model the relationshipbetween ambient conditions and...
Dependable Production of Air-Entrained Concrete with High Resistance to Freezing and Thawing in the Presente of De-Icing Salt For Road and Bridge Construction
To ensure that concrete has a high resistance to freezing and thawing it must contain small air voids which are produced by an air-entraining agent and which must be present in sufficient quantities to match the amount of fine mortar. The limits for the air content of unset concrete and...
The Chemical Characterization of Admixtures For Cement Concrete
Although the Belgian standards provide for quality control of idrnixtures for cement concrete, it is interesting to complement his information by a more thorough chemical identification. this makes it possible to increase the economic advantages vhich result from their use. nfrared spectrographic investigation, which enables the ategory of basic chemical...
Current Trends and Criteria For the Selection of Materials For Concrete Pavements
The object of this articleisto evaluate the influence of materials used in the construction of rigid pavements, and of the method of placing the con-crete on the final pavement quality.Using the results of laboratory tests and experi-ments taken from the available literature, the ut-most attention must be paid to the...
High Strength Aggregate Rich Concrete For Pavements
During the last decades the use of Roller Compac-ted Concrete for pavements has increased worldwide. A concrete pavement of significant higherquality than typical Roller Compacted Concretehas been developed at Aalborg Portland. The con-creteisplaced and fullycompacted with an asphaltpaver, mounted with a heavy high-compactionscreed. No rollers have to be used. In...
Resistance of Concrete Safety Barriers and Concrete Road Against the Scaling Action of Deicing Salts
The paper presents a synthesis of results related to the construc-tion of concrete safety barriers and of a study about the treat-ment of roads in which the strength against deicing salts wastoo low.A survey of the 13 concrete safety barriers after 3 wintersshows that there is a rather good relation...
Porous Concrete For Urban Pavements
Over the past few years, interest in the uses and applications of porous cement concrete for pave-ments has been growing. Its position in pavementconstruction has developed to such an extent thatit iscurrently used in places of greater importance(from shoulders to sub-bases, and even surfaces).This paper is part of the experience...
Cements For Concrete Pavements Mixed Cement Or Type V with Fly Ash
In Spain the development of cement, specially for concrete pavements, has been based on making use of fly ash in cement production. Such a development was achieved after studying the characteristics of the available fly ash and the respective experiencies. The results led to a widespread use of this type...
Quality Assurance of Construction Materials For Concrete Roads in Germany
Heavy use of the pavements caused by traffic, cli-mate and winter service requires a highly resistantconcrete with high flexural strength. Correspon-ding requirements on road concrete are laid downin «Additional Technical Instructions for Cons-tructing Concrete Pavements» (ZTV Beton), partlyalso requirements on some concrete basicmaterials.All materials used for construction of concretepavements have...
High Strength Concrete For Highway Pavements Ano Bridge Decks
An accelerated road-wear simulator employed by Norcem for experimental testing of abrasion resistance of highway concrete pavements subjected to heavy traffic by studded tyres was set up at Slemmestad, Norway in 1985. By increasing concrete strength from 50 up to 120 MPa, the abrasion was reduced by roughly 60-70 %....
Developments in Noise Redution of Concrete Roads in the Netherlands
In the Netherlands experiments have been performed recently :onceming noise reduction on concrete roads. Three pos-.ibilities are being investigated:I. Top layer of no-fines porous concrete.~. Surface of washed dense concrete.. Dense concrete with fine-grained epoxy surface treatment. noise emission level slightly higher than on porous asphalt,iut much less than on...
Porous Urban Pavements in Cement Concrete
Questions regarding the environment are being particularly felt in certain countries, and noise con-trol requirements have led to the development ofthin free draining materials able to limit tirepavement contact noise.We shallbe dealingherenotwith a thin free draining pavement structure, butwith a porous concrete pavement of 40 cm thick-ness. Theoretical studies have...