Valoración de las cenizas de carbón para la estabilización de suelos mediante activación alcalina y su uso en vías no pavimentadas

Abstract

With the purpose of obtaining a new stabilizing material for tertiary network in Colombia, which is built on material footing and is in a critical condition from lack of maintenance due to poor investment for road infrastructure, this paper discusses the purpose of evaluating alternative stabilizing materials for tertiary network. The coal ash is one of the largest waste generated by industries, so it has a lot of this material for disposal. This residue was shown to possess pozzolanic properties with an alkaline activation. This was the reason that the realization of this work was necessary in order to evaluate, estimate and determine the mechanical behavior of coal ash as a soil stabilizer and assess their ability to withstand the loads transmitted by the vehicles. It was analyzed the effect of an alkali activated coal ash in different soil types over the Unconfined Compression Strength (UCS). The results of the modified Proctor test and UCS of clay soils, and sand are presented and discussed and a representative soil pathway study in Red INNOVIAL project of the Municipality of Urrao, which it will be called “Urrao”, all soils are added with coal ash with the variety of 7%, 14% and 21% and 7 days later it’s UCS is determined. By statistical analysis, the results are analyzed to identify the factors that influence the most on the variable response in each soil. A comparison was made between the results obtained by different soil types and dosages of coal ash used in the study, in addition to the influence by the kind of alkali activator that was used. It was found that in order to coal ash to mix with gravel, clay and Urrao soils must be filtered by No. 100 mesh or more and using sodium hydroxide as an alkaline activator solution at a concentration close to 8 MOLAR to obtain a cementitious material with characteristics comparable with the INVIAS Standard, Article - 350.4.1. Finally conclusions and recommendations were made regarding the issue.