Recovery of construction and demolition waste as recycled aggregate for concrete manufacturing
This article discusses the findings of a feasibility study on the partial replacement of natural coarse aggregate by a recycled aggregate from construction and demolition waste in the manufacture of concrete of 30 MPa strength grade. Workability, density, mechanical behavior (compressive and tensile strength) and total water absorption were studied in a series of concretes containing 25 and 50% of the recycled aggregate with and without floating materials. The results showed that using up to 50% of the recycled aggregate had no adverse effects on fresh concrete workability. Hardened concrete density and compressive strength were observed to decline with increasing replacement ratios, due to the ITZs between constituents of recycled aggregate/paste are weaker than natural coarse aggregate (gravel)/paste.
Respect to the total absorption water the recycled concrete was higher than conventional concretes. Overall, considering the strength and other properties achieved, the concretes containing the mixed recycled aggregates studied were found to be apt for housing construction. The technical, economic and environmental improvements stemming from the potential replacement of natural coarse aggregate with such recycled construction and demolition waste would contributed to the sustainability of the construction industry.
EQUIPMENT PROVIDERS 1
Bag filters in cement works
There is little news in bag filters applied to cement works, perhaps the most interesting one is the increase of the use of alternative fuels. This change concerns ambient filters and also leads to variation of components in kiln gases, variation that turns the filter into a chemical reactor.
In this article, Gorco presents a short summary of bag filters used in the cement industry that may help Cemento Hormigón junior readers.
EQUIPMENT PROVIDERS 2
FlSmidth Iberia, local service expersite
FLSmidth hold a Symposium during days 25 and 26 of March at our premises located at Las Rozas-Madrid. This meeting was aimed at both sharing with our customers the FLSmidth knowledge and fostering exchange of ideas and cases between the different cement groups.
The Seminar included a whole overview of the most important topics related to maintenance and services related to ball mills, vertical mills, gear boxes and automation. The presentations, made by skilled experts, specifically included subjects like corrective and preventive maintenance best practises, spare parts recommendations, mills performance improvements obtained by using Advanced Control Systems, maintenance possibilities by means of remote services and monitoring, etc. Furthermore a broad range of case stories were also presented to the attendees. Over 30 cement customers from Spain and Portugal attended the Symposium.
It was also underlined that FLSmidth Iberia has been updated to the present challenging markets, so further to our traditional offer of green field projects and big retrofits, we currently support a full range of services to our cement and minerals customers.
Through our four operational Divisions, Cement, Automation, Air Polution Control and Minerals and fully supported by the FLSmidth´s Technical Centres located in US, Europe and India, we act as a one source provider of equipments, projects and services in the cement and minerals sectors.
EQUIPMENT PROVIDERS 3
CleanSpace2™, a major innovation in respiratory protection systems
Expert in personal protective equipment, ROCHER SERVICES has over 10 years of experience. We understand that respiratory protection should be comfortable, safe and easy to use. Innovation and providing the highest quality products is at the heart of everything we do thanks to our partners. CleanSpace2™ builds on a combination of technologies found in today’s industrial respirators, medical respiratory devices and consumer electronics. Our products aresafe, robust and high performing, even in the harshest environments. Our dedication to reliability and quality is reflected in the Company’s Quality Management System, which is accredited to the globally recognized ISO 9001 standard.
A major innovation in personal respiratory protection, a compact and light weight power unit is cushioned around the back of the neck, counter-balancing the soft silicone low profile mask and providing fresh, clean air, on demand, as you breathe. This unique method of personal respiratory protection delivers significant benefits to workers in industry.
EQUIPMENT PROVIDERS 4
Efficiency and sustainability for the cement industry
The cement industry is one of the most demanding industries. Control and measurement of energy consumption is a key issue to make more efficient and sustainable the production process. Schneider Electric, a global leader in energy management and energy efficiency, develops solutions to reduce companies’ consumption to be more competitive and respond to their sustainable development objectives. Experts in systems architecture design, automation, process control and energy efficiency, have been developing performance and cost-optimised solutions for the cement industry for many years. These solutions meet the needs of Production as well as Engineering and Maintenance, enabling them to concentrate on their core activities and achieve their specific objectives.
Characterization of concrete 3000 psi (20 Mpa) by X-ray difraction
Common concrete is produced by mixing the three essential components: cement, water and aggregates. The thermal properties, chemical and physical properties of aggregates can modify the mechanical properties of concrete such as structural strength and durability of concrete. In this work, a study of the structural properties of 3000 psi (20 MPa) concrete and its separate components: cement, gravel and sand. This material is often used in the construction industry for foundations, columns and beams high. Crystallographic characterization through measurements of X-ray diffraction (XRD), using the High ScorePlusX'pert program of PANalytical.
Model for Standard Environmental Risks Report developed for the spanish cement manufacturing sector
Following the publication of the Royal Decree 2090/2008 of 22 December, which approved the regulation of partial development of Law 27/2007 of 23 October on Environmental Liability, the Asociación de Fabricantes de Cementos de España - Oficemen (Spanish Cement Association) decided to develop a Model for Standard Environmental Risks Report (known by its Spanish acronym MIRAT) that would enable operators of cement sector to have a practical tool to perform an environmental risk assessment in order to take the necessary measures to prevent environmental damage or to take the necessary restorative measures if it has occurred. This article summarizes the MIRAT developed for cement activities.
Application of biomass olive bottom ash to recycled soil-cement for roads
Nowadays the recovery of waste generated by the industrial sector is becoming very interesting to transform these products into new raw material alternative.
Andalusia, leading the power generation from biomass combustion. Consequently, the removal of the ash produced by the combustion of biofuels has become an environmental and economic problem. However, its potential for reuse is conditioned by their physical- mechanical properties.
The waste generated by the combustion of biomass can be classified fly ash (CVB ) and bottom ash (CFB ) . The CFB is more generated, but currently have no alternative use. The aim of this study was to evaluate the technical feasibility of the use of CFB as building material and in particular, in making soil cement. For this purpose, the properties that define each of the materials and whose values limit its use for this application idea further evaluate, based on the results, the suitability of this material for the intended use or potential analyzed alternative uses. In addition, a study was conducted to evaluate the power of these ashes auto-cement manufacturing mortars with different percentages of recycled soil cement replacement.
The results demonstrate that while no significant cementations provide capacity using CFB soil cement can be a viable solution to these products.