A freeze-preventing material comprises cement, salt, and water-absorbing resins. The freeze-preventing material is scattered on the pavement surface in the form of slurry to prevent the pavement surface from freezing. Thereby a freeze-preventing effect is maintained for a long period of time owing to the water-absorbing resins which absorb and retain the salt in large amounts. The anti-freezing effect can be restored by spraying the pavement with the salt again.

A concrete composition which has superior fluidity and filling property and from which a concrete structure having high quality and durability and being excellent in resistance to freezing and thawing can be made without compaction by vibration. The composition comprises cement, water, aggregate, at least one admixture selected from the group consisting of a water reducing agent, an air entraining agent, an air entraining water reducing agent and a superplasticizer, and at least one viscosity improver of a cellulose type of viscosity improver having a low foaming property which shows specific viscosity and an acrylic type of viscosity improver having a low viscosity which shows specific viscosity in a specified amount.

Disclosed are methods of reducing water penetration through civil engineering structures which comprise applying to the structures a waterproofing agent pretreatment composition including acrylic or vinyl acrylic latices and various freezing point depressing agents. Also disclosed are packages including these pretreatment compositions and methods for using these pretreatment compositions to waterproof various civil engineering construction materials.

Bei der vorliegenden Erfindung wird ein Verfahren zum Schutz poröser Baustoffe gegen Tausalzeinflüsse vorgeschlagen, bei welchem ein wasserdampfdiffusionsfähiger Belag aus einer Imprägnierung und einem darauf angeordneten Wachsbelag zumindest auf die zur Wetterseite weisende, sichtbare Oberfläche des porösen Baustoffes aufgebracht wird.

Verfahren zur Herstellung von Poren enthaltenden Festkörpern aus einem Gemisch von Bindemitteln, vorzugsweise Zement, Zu­schlagstoffen sowie gegebenenfalls an sich bekannten Hilfs- und Zusatzstoffen durch Zugabe von Wasser, Verformung und ge­gebenenfalls Verdichtung der entstehenden Masse und Aushär­tung derselben. Um eine gute Frost-Tausalz-Beständigkeit der Festkörper zu erreichen, wird vorgeschlagen, im Festkörper ein Porensystem aufzubauen, indem ein trockenes, zumindest teilweise wasserlösliches und/oder mit Wasser Gelteilchen bildendes Granulat aus unvollständig gehärtetem Harnstoff-­Formaldehyd-Harz zugemischt wird.

A carbon fiber-reinforced hydraulic composite material having excellent mechanical strength, workability, and freezing-and-thawing resistance, wherein chopped carbon fibers having a monofilament tensile strength of from 140 kg/mm² to 270 kg/mm², and a monofilament diameter of from 15 µm to 30 µm are blended as the carbon fibers at a ratio of from 1% to 4% by volume with respect to the entire composite material to bring a flow index of the composite material before its hardening to 120 mm or above.

A phosphate additive, such as apatite or mono­calcium phosphate monohydrate, is used to treat concrete aggregate and concrete to improve its resistance to natural and salt induced breakdown. The phosphate can also be used in association with road salt to prevent spalling and breakdown of concrete surfaces and damages to cars. Used alone as a surface treatment, it has the same effect.

A phosphate additive, such as apatite or mono­calcium phosphate monohydrate, is used to treat concrete aggregate and concrete to improve its resistance to natural and salt induced breakdown. The phosphate can also be used in association with road salt to prevent spalling and breakdown of concrete surfaces and damages to cars. Used alone as a surface treatment, it has the same effect.