Page 133 - New Trends in Green Construction

New Trends in Green Construction
NEW NANOMATERIALS FOR SOIL STABILIZATION IN CIVIL ENGINEERING
Manuel Cabrera, Julia Rosales1 Adela P. Galvín, Antonio Ramírez, Francisco Javier Mateos, Francisco Agrela
Keywords: Soil stabilization, Expansive soil, Clay soil, Nanomaterials 1. Introduction
The soil treatment techniques contribute to the competitiveness and sustainability of road engineering (Maestro and Ibañez, 2009). The material characteristics must satisfy the engineering functions that contribute to the durability and quality of the entire road structure (François and Jullien, 2009).
Extensive studies have been carried out regarding the treatment of expansive soils using various additives, such as lime, cement, fly ash, industrial waste products, potassium nitrate, calcium chloride and phosphoric acid (Croft, 1967; Sherwood 1993; Cabrera, 2018).
During the last years, there has been a great interest in nanoparticles due to the numerous technological applications that also tried to achieve an ecological and low cost. These useful features of the synthesized nanoparticles can benefit the engineering sectors (Kajbafvala et al., 2013).
This study presents the results of an investigation on the effects of the addition of nanomaterials in expansive soil in its plasticity limit, compaction characteristics, unconfined compressive strength and bearing capacity.
2. Materials
2.1 Expansive clay soil (ECS)
Expansive soils are those which show volumetric changes in response to changes in their moisture content. Such soils swell when the moisture content is increased and shrink when the moisture content is decreased. The expansive clay soil analysed comes from Villacarrillo (Jaen), Andalusia.
2.2 Quicklime (Q)
Hydrated lime is obtained when quicklime reacts chemically with water. Hydrated lime (calcium hydroxide) reacts with clay particles and permanently transforms them into an strong cementitious matrix.
2.3. Nanomaterials (N)
Liquid additive that, in combination with cementitious materials, is used to stabilize soils by increasing the mechanical properties of the soil.
3. Methods and results
The following parameters were measured to physically and mechanically characterize the samples: granulometric, absorption, density, Modified Proctor test, bearing capacity based on the CBR index, plasticity, compression strength test and fluorescence spectrometry.
133