A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
A New Efficient and Safe Admixture for Freeze/Thaw Resistant Concrete
Abstract Frost or freeze/thaw exposure can cause serious damage to a concrete structure. De-icing salts attack concrete surfaces and are one of the most damaging causes for concrete structures. Through appropriate structural technique and observance of basic technological measures pertinent to concrete, the building material can demonstrate permanently high resistance to frost and to the strain which de-icing salt represents. One solution to increase the frost and freeze/thaw resistance is the use of an air-entraining admixture. Air-entrainers for concrete applications have been around for decades. Back in the last century, first trials showed that a good air-entrainer could be made of resins refined from wood resin. In the last year decades the use of synthetic air-entrainers has gained momentum. The creation of artificial air voids with natural and synthetic air-entrainers are based on physical effects. The air content as well as the air void size will be influenced positively as well as negatively by many parameters like type of admixture, chemical variations concrete raw materials, water quality, temperature, aggregates, cement, mixer type, mixing time, and many more. Recently a new type of air-entraining admixture has been developed which entrains air voids based on a chemical reaction, these air-entrainers are called as active air-entrainers. In contrast to the commonly used air-entrainer, active air-entrainers have the advantage of producing always the same quantity and quality of air voids required with all kind of aggregates, cements, admixtures and other influencing parameters in order to obtain finally a frost and freeze/thaw resistant concrete. The active air-entrainers produce even sized uniformly distributed micro air voids throughout the concrete matrix. This paper provides general information about active air-entrainers, its mechanism and presents some of the laboratory and field test data.
A New Efficient and Safe Admixture for Freeze/Thaw Resistant Concrete
Abstract Frost or freeze/thaw exposure can cause serious damage to a concrete structure. De-icing salts attack concrete surfaces and are one of the most damaging causes for concrete structures. Through appropriate structural technique and observance of basic technological measures pertinent to concrete, the building material can demonstrate permanently high resistance to frost and to the strain which de-icing salt represents. One solution to increase the frost and freeze/thaw resistance is the use of an air-entraining admixture. Air-entrainers for concrete applications have been around for decades. Back in the last century, first trials showed that a good air-entrainer could be made of resins refined from wood resin. In the last year decades the use of synthetic air-entrainers has gained momentum. The creation of artificial air voids with natural and synthetic air-entrainers are based on physical effects. The air content as well as the air void size will be influenced positively as well as negatively by many parameters like type of admixture, chemical variations concrete raw materials, water quality, temperature, aggregates, cement, mixer type, mixing time, and many more. Recently a new type of air-entraining admixture has been developed which entrains air voids based on a chemical reaction, these air-entrainers are called as active air-entrainers. In contrast to the commonly used air-entrainer, active air-entrainers have the advantage of producing always the same quantity and quality of air voids required with all kind of aggregates, cements, admixtures and other influencing parameters in order to obtain finally a frost and freeze/thaw resistant concrete. The active air-entrainers produce even sized uniformly distributed micro air voids throughout the concrete matrix. This paper provides general information about active air-entrainers, its mechanism and presents some of the laboratory and field test data.
A New Efficient and Safe Admixture for Freeze/Thaw Resistant Concrete
Schwoon, Oliver (author)
2017-08-06
7 pages
Article/Chapter (Book)
Electronic Resource
English
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