Review of the European norm of specifications of common cements EN 197-1:2000
The result of the first revision of EN 197-1:2000 is presented. This draft of standard will be send to final vote by the end of 2010 and, probably, it will became the EN 197-1:2011.
Study of anhydrous and hydrated cements by Raman spectroscopy
A review of Raman spectroscopy application to qualitative analysis of anhydrous and hydrated cement phases is presented in this work. Raman spectroscopy is a vibrational technique that yields information on molecular structure that allows poorly ordered materials characterization, like C-S-H gel.
Anhydrous phases study is complex due to fluorescence problems. The use of Micro-raman gives information of some micros depth of the sample with low level of interferences, and then fluorescence problems have been minimized. Finally, it is a technique easy to perform either on powders and manufactured products; it requires only small sample amounts, no sample preparation and allows low detection limits.
Permeable concrete: considerations for the design of mixtures, design of the thickness of pavement and methods of test
The permeable concrete is a mixture of aggregates, cement and water, in suitable amounts to create a mass of particles of aggregate thickness that stays adhered by a thin layer of paste. Generally, the permeable concrete mixture contains little or nothing of barren fine, which generates a great content of emptinesses, forming porous structures that allows to create a vacuum system interconnected with high permeability allowing the infiltration of the water coming from precipitations. The permeable concrete is used traditionally in parking and light transit areas.
Nowdays, it use has been increased beacuse it is considered as a sustainable construction material. Due to the increase in the use and application of the permeable concrete, recently recommendations have been developed on the design of mixtures, design of thickness of pavement and methods of test to characterize
and to validate this type of concrete.
This article presents the most excellent aspects to consider in the design of mixtures, design of the thickness of pavement and the present state of the existing and developing methods of test for the permeable concrete.
State of Art of CCS technologies. Application to cement industry
Continuous growth of main economies in the World meant an increment in the demand of energy and construction materials. In this context, industrial sectors and, specifi cally, cement sector are developing alternative technologies so as to reduce GHG emissions, contributing this way to increase global sustainability of the system.
Heavy metals pathways in cement production to enhance a sustainable valorization of alternative materials
This article presents a study of the evolution of the emission profile of a cement plant that operates in continuous process and using alternative materials. The study was focused on determining the presence of heavy metals in order to develop and establish a methodology for indirect characterization of trace metals and particle size distributions, as a function of raw materials and fuels fed into the process as the basis for
waste management in Lemona Industrial S.A. cement plant.
The study was carried out after several sampling campaigns developed over 7 years with data from different process flows, where it shows the changes made in the production process with the change of the air pollution control system and the use of different alternative fuels with the report of the data from process flows. (...)
Cemex’s EcoOperando label
This paper describes how Cemex Spain created the label EcoOperando, as a response to the society’s demand for more sustainable products. In our case, we stressed the savings in CO2 emissions, looking for a label that enables our clients to identify our products aligned with this requirement.
The criteria for the label awarding and the reasons to choose those criteria are detailed explained. This initiative was combined with the launching of a new paper bag. Besides, paper describes the related communication plan to our clients.
Subgrade stabilization and pavement recycling for the cross section enlargement in the A-495 road (Gibraleón – San Bartolomé)
The original project of the A-495 (Gibraleón – San Bartolomé) upgrade consists in an improvement of the cross section (from 6 metres, in the fi rst work, to 8 metres in the second one, and to 10 metres in the actual work) and a reinforcement of the road surface. The method for the cross section enlargement consists, in the original project, in a re-grown using aggregates for the subgrade.
The diferent stiffness in the cross sections could produce longitudinal crack like occurred in the past when the first regrown was made. Also, the aggregates needed are far away from the location of the road. These problems (and others) resulted in a change in the originals plans. The original subgrade and the re-grown one were treated with cement in order to obtain a stabilized soil. Also, the existing pavement would be recycled and used like a soil-cement layer in the pavement. The road surface was constructed with asphalt agglomerate over this stabilized soil (subgrade) and the soilcement (pavement).
Pavement recycling really constitutes a more competitive, suitable and sustainable alternative for pavement rehabilitation than the convencional reinforcement. It is possible to use natural aggregates near the zone, avoiding the creation of residues and obtaining a better subgrade and pavement layers.