Análisis de trabajabilidad/ resistencia/ y costos de mezclas para hormigones de elementos prefabricados con el uso de aditivos

Abstract

The present project focused on the analysis and design of concrete used for prefabricated elements with the implementation of water-reducing additives. The case study arose from the need to define an optimal dosage since the company currently does not have one, as their mix designs are empirical. The aggregates used in the mix designs were properly characterized and met the requirements set forth in ASTM C33. A concrete mix was designed with a stress of 300 kg/cm2 according to ACI 211.1. The water-to-cement ratio was kept constant in each design, and additives with different ranges of water reduction were implemented, ranging from medium, high, to superplasticizer. The additives selected were Plastocrete 161 HE, Sikament HE200, and ViscoCrete 4100, respectively, all from the brand Sika. Once the results of each proposed design were obtained, the properties in the fresh and hardened states were analyzed, as well as the cost per m3 of each mix. It was concluded that from an economic and strength perspective, the best alternative was the design that contained the ViscoCrete 4100 additive in its composition, as the price of the concrete per m3 was only $49.59 and its early-age strength was superior, reaching 225 kg/cm2

, which represents 75% of the required strength. After 28 days, it exceeded the required strength, reaching 402 kg/cm2