Summary 

Nowadays, the use of agricultural and/or industrial wastes in the production of binders is a topic of growing interest. It is due, on one hand, it allows managing some types of wastes realising landfills and, on the other hand, because it reduces the environmental impact caused by the production of Portland cement clinker, in particular as it relates to the CO2 emission.

This work provides a study on the reuse of a glass fiber manufacturing waste (VCAS) in the production of binders for use in civil construction. To facilitate reading and understanding of the work, it was shared into three main parts: characterization of VCAS, Portland cement binders and alkali activated binders.

The first part presents the main objective of characterizing the VCAS from a physical-chemical point of view. From these parameters has been able to understand the possibilities of application of this material in the production of binders. VCAS is an amorphous material with high content of SiO2, Al2O3 and CaO.

In the second part, we analyze the hydraulic/pozzolanic properties of VCAS in systems based on lime/mineral admixture or Portland cement/mineral admixture. It has been shown that VCAS is a mineral admixture that presents a pozzolanic reactivity which is increased for long curing time or high curing temperatures. The influence of VCAS percentages, curing time and temperature, water/binder ratio, sand/binder ratio were some of the parameters analyzed in this part of Doctoral Thesis. In general, it can be established that amounts of 10 and 20% of VCAS, allows to achieve materials with excellent properties. Note, on one hand, that at this stage of work was also developed a new method to characterize the mineral admixtures by monitoring aqueous suspension of lime:pozzolan by pH and electrical conductivity measurements. From this new method was possible to distinguish the reactivity of pozzolans analyzed.

In the third part of work, which is the most extensive and mayor contribution of the Tesis, we propose the use of VCAS as an aluminosilicate source material in the production of alkali activated binders. Mentions that were analyzed the influence of the alkaline activator and curing conditions on the production and preparation of alkali activated binders based on VCAS. Thus, it is demonstrated that geopolymerization process of VCAS can be activated at 65ºC using Sodium and potassium hydroxide solutions. Also, note that it has demonstrated the great efficiency in the development of compressive strength of mortars activated with sodium silicate solutions. In the same way, it was developed activating solutions for VCAS geopolymes which allows the setting and hardening process of these materials at room temperature. Preliminary studies on the durability of these binders were also performed, showing that the material has a higher resistance to acid attacks, compared to Portland cement. Note that were yielded compressive strength values greater than 100Mpa for mortars prepared with the optimal conditions (3 days at 65ºC, relative humidity above 95%).

The obtained results in this research can pointed out to the feasibility of use VCAS in the production of binders from scientific and technologic point of view. Both, as partial replacement or as a total substitute of Portland cement, it is observed that the VCAS has suitable characteristics for its use in the civil construction.