Analysis of the behavior of Type I cement with the addition of feldspar: bleeding, heat of hydration and compressive strength

Sleyter Medina Cabanillas E.; Natal y Carrión Rabanal K. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2025) · DOI: 10.18687/laccei2025.1.1.1006

Resumen

In the present study, the influence of the use of feldspar as an addition to Portland cement in the preparation of concrete with a fluid consistency design and compressive strength of f´c=250 kg/cm2 was investigated. The effectiveness of adding feldspar to Type I cement in proportions of 5%, 10% and 15% with respect to the weight of cement was evaluated, analyzing its exudation at room temperature. For this purpose, 12 specimens were prepared which were subjected to the concrete exudation test. Where values were obtained for the Base Concrete (BC)= 0.34%, addition of 5% Feldspar (C5F) = 0.33%, 10% Feldspar (C10F) = 0.326% and 15% Feldspar (C15F) = 0.32%. In addition, the bleeding rates and their associated equations were determined for each dosage CB=0.0132 cm/s, C5F=0.0075 cm/s, C10F=0.0076 cm/s and C15F=.0.0054 cm/s. The results showed that a higher addition of feldspar reduces both bleeding and its rate, with C15F being the mixture with the lowest bleeding. In addition, compressive strength tests were carried out at 3 and 7 days on mortars made with the proportions of feldspar, obtaining a higher resistance of approximately 10% with a dosage of 10% addition. Feldspar reduces bleeding and heat of hydration, which can minimize thermal cracking in massive structures. For the moment, this addition is defined as a modification of Type I cement, considered as a mixed cement since it shares properties of Type III and Type IV cements, which are high initial strength and low heat of hydration. This study contributes to the development of more sustainable materials, since the use of feldspar could optimize the performance of concrete in hot climates and reduce the environmental impact by taking advantage of mineral by-products, favoring durability and efficiency in construction.

Instituciones: Universidad Privada del Norte