Study on the hydration reaction and pore structure of ecologically recycled mortar with corn cob aggregates

Abstract

Ecologically recycled mortar with corn cob aggregates becomes a research hotspot. However, corn cobs consist of organic materials which have a negative impact on the hydration process of cement. Therefore, a knowledge of the effects of corn cob particle dosage on the hydration reaction process and microscopic pore is important. In this study, nuclear magnetic resonance (NMR) was used to quantitatively and visually observe the hydration reaction of the mortar, and it was found that the addition of corn cob particles resulted in a 22-fold increase in harmful pores and a 20% decrease in pore complexity. Moreover, the effects of corn cob particles on self-shrinkage after the exothermic hydration of mortar was investigated. The result demonstrates that mortar with corn cob particles exhibits a certain degree of plasticity and can bear a certain amount of load, while retaining up to 20% of its deformation energy. Despite the decrease of strength, high admixtures of corn cob particles have excellent thermal insulation properties. This attribute endows corn cob pellet eco-mortar (EM) with the ability to resist external loads, such as those caused by earthquakes and uneven settlement, and thus, provides this material with the potential to be utilized as a wall material.