http://www.personal.psu.edu/faculty/g/u/gur/cement%20for%20the%20future.pdf

Alkali-activated fly ashes: A cement for the future

The Role of Inorganic Polymer Technology in the Development of ‘Green Concrete’

Understanding the relationship between geopolymer composition, microstructure and mechanical properties

Advances in alternative cementitious binders

New cements for the 21st century: The pursuit of an alternative to Portland cement

http://digital.csic.es/bitstream/10261/210858/1/radiomorta.pdf

Radiological behaviour of pigments and water repellents in cement-based mortars

A clear alternative to reach the goal of sustainable development in the Construction Sector is the development of alternative building materials to Ordinary Portland Cement (OPC) in a more energetically as well as environmentally eco-efficient way. Alkaline cements (Alkali-Activated Materials, AAMs) and geopolymers meet these requirements; and they are based on the alkali activation of aluminosilicates (mainly waste and industrial by-products, such as blast furnace slag, fly ash and ceramic waste) in highly alkaline solutions. AAMs cements and concretes are notable for being very durable and mechanically resistant. However, to date their rheological behaviour is not well controlled and there is little understanding of it, with very disparate experimental data. Despite this, their rheological behaviour is not fully understood and little is known on the disparate data obtained in AAM pastes. Moreover, the common additives used in the preparation of OPC concretes and the rheology modifiers/controllers are also unstable in the AAMs systems.Understanding and controlling the rheology of the AAMs systems will ultimately determine whether they can be implemented in the market, and will open up greater competitive possibilities in a crisis-affected sector. A systematic study of the factors that affect the rheological properties of AAMs (pastes, mortars and concretes) is therefore necessary in order to ultimately develop more resistant and durable materials.

/pdf/rheology-of-cementitious-materials-alkali-activated-5c0l7fo2t5.pdf

Rheology of Cementitious Materials: Alkali-Activated Materials or Geopolymers

/pdf/effect-of-curing-temperatura-on-hydration-process-of-3sy2kx5eei.pdf

Effect of curing temperatura on hydration process of different cement

The present paper addresses the alkali activation of Portland cements containing blast furnace slag (20 and 30% of the cement by weight) with a view to the possible use of these materials in oil well construction. 

The hydration studies conducted showed that in cement/slag blends, the sodium silicate activating solution partially inhibited the dissolution of the silicate phases in the Portland cement, retarding cement hydration and reducing the precipitation of reaction products. Due to such partial inhibition, the cement/slag blends had significantly lower mechanical strength than Portland cements hydrated with water. 29 Si and 27 Al MAS NMR and BSE/EDX studies, in turn, showed that the C-S-H gel forming in the alkali-activated cement/slag pastes contained Al in tetrahedral positions and low Ca/Si ratios.

/pdf/characteristics-and-propierties-of-oil-well-cements-1ctbs9hdgc.pdf

Characteristics and propierties of oil-well cements additioned with blast furnace slag

The choice of a superplasticiser (SP) for concrete is of great complexity, as it is well known that properties of the end product are related to admixture and its compatibility with concrete components. Very few studies have been conducted on the compatibility between SPs and the sand of mortars and concretes, however. Practical experience has shown that sand fineness and mineralogical composition affect water demand and admixture consumption. Clay-containing sand has been found also to adsorb SPs, reducing the amount available in solution for adsorption by the cement. This study analysed the isotherms for PCE and BNS superplasticiser adsorption on four sands with different fineness and compositions commonly used to prepare mortars and concretes. BNS-based SP did not adsorb on sands, while PCE-based admixtures exhibited variable adsorption depending on different factors. The adsorption curves obtained revealed that the higher the sand fineness, the finer the particle size distribution and the higher the clay material, the greater was PCE admixture adsorption/ consumption.

/pdf/pce-and-bns-admixture-adsorption-in-sands-with-different-quni1202tt.pdf

Francisca Puertas

Papers

Radiological behaviour of pigments and water repellents in cement-based mortars

Rheology of Cementitious Materials: Alkali-Activated Materials or Geopolymers

Effect of curing temperatura on hydration process of different cement

Characteristics and propierties of oil-well cements additioned with blast furnace slag

PCE and BNS admixture adsorption in sands with different composition and particle size distribution