Mix preparation for higher strength concretes for transport infrastructure

Abstract

The paper proposes an effective technique for the production of higher strength concrete for the construction of transport communications with increased operational characteristics. It is suggested to use a centrifugal rotary mixer for the preliminary thorough mixing of the estimated amount of concrete and sand with natural humidity of 3–5%. Such a mixer allows mixing damp sand and dry cement, thereby providing the required mixture flowability. When collided at a high speed, the cement and sand particles disintegrate to a smaller size due to the mechanical milling and abrasive properties of sand particles. During the mixing process, nanodispersed hydration products adsorb on the surface of cement particles due to cement hydration, and then are sanded off and delivered to the cement mix. Being thus enriched with nanodispersed particles, the sand-cement mix is characterized by rather a uniform cement distribution in its all microvolumes. The sand-cement mix with the addition of a coarse aggregate and estimated amount of water provides a significant improvement of the concrete strength and other properties.