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Show Different Ways to Cure Newly riaced Concrete Keeent survey of numerous highway high-way construction projects show that contractors employ dlfferen' methods to cure newly-laid concrete. Thin eur-ti eur-ti Is said to be one of the very Important Im-portant processes In building a first-class first-class concrete pavement. On level sections of highway, the preferred method, It was found, Is the building of earth dykes along the edges of the pavement and flooding the Inside In-side area as shown In the Illustration. The water Is then kept on the surface of the concrete for ten days or two weeks. This method was thought f he cheaper than covering with earth because of the labor necessary to shovel the dirt on to the pavement and later clean It off. The water required re-quired to keep the enrth wet was about as much as If the surface of the pavement was flooded. Some contractors reported that the use of hay wag best. They said It would hold more water and could be 4- Y I fir vi ? k. i. i ' , v S v - , V i I- H I 'Ttvf. "t ' i -fi 1 t .w J? v -. i v v ' t :'.' sv. i I Curing Newly-Laid Concrete by Flooding. Flood-ing. used several times over. Moreover, It was not hard work to distribute the hay or rake It up after the curing I period. ( Where water was plentiful, some ' contractors expressed themselves In ( favor of using sprinklers. A water j pipe was laid down the center of the road, with lawn sprinklers attnehed at j frequent Intervals. These were kept j running several hours a day. j The advantage of one or another j method of curing were not found to be such as to affect the strength or wearing qualities of the concrete. Although Al-though concrete begins to harden soon after it is mixed, the full strength Is developed by progressive hardening over a period of time. The hardening process Is said tf be not a drying process, as the presence of moisture Is necessary to assist the chemical action which causes concrete to harden. |