Air Binder Research Articles

Physico-mechanical and physico-chemical hardening process changing research in gypsum binder and transition in gypsum-cement binder and then to gypsum-cement-pozzolanic using with mechanical tests and x-ray spectroscopy

Gypsum-Cement-Pozzolanic binder (GCPB) has been invented in 60-s of last century in USSR by group of scientists under Mr. A. Volzhenskiy leadership. In that time in USSR and actually in US construction technological processes of civil and industrial buildings increasing a lot. So demand of cement for heavy concretes as a main component high up day to day, year to year. But realisation of that idea in practical way wasn’t easy thing because as we know from «Material science» course – cement is hydraulic binder which hardening in moisture condition or in must cases in water and if we sae about gypsum is an air binder. That means gypsum is hardening and gets its high compression strength in air condition and loosing that strength in moisture condition or under influence of water. After analysing knowledge that have been written above about GCPB we may stay some problems in front of us: 1) First problem connect with modern theoretical physical-mechanical and physical-chemical researches absence, when GCPB hardening process have been described by modern X-Ray spectroscopy and mineralogical analysis. All what we have found in internet resources is basic and theoretical issue with some mechanical tests. 2) Also the main problem when we start see on that researches and mechanical tests, there are some conflicting things as links for technical requirements of GCPB through ages, storage conditions before tests. So according by what we have said above we choose some targets of our research: a) How gypsum binder’s physical-mechanical characteristics going to change as it would be main stuff for GCPB preparing. And also transition process gypsum binder(GB) in gypsum-cement binder (GCB) and then in gypsum-cement-pozzolanic binder (GCPB); b) How gypsum binder’s physical-chemical characteristics going to change during transition process in GCB and then into GCPB with X-Ray spectroscopy analysis.

The Influence of Dry Hydrated Limes on the Fresh and Hardened Properties of Architectural Injection Grout.

Dry hydrated lime is an air binder often used in architectural injection grouts. This study compared the influences of three commercially available dry hydrated limes on the injection grouts’ workability and mechanical properties. The main differences between the limes were in their chemical and mineralogical composition and Blaine specific surface area. The grouts were composed of dry hydrated lime, finely ground limestone filler, water, and super plasticiser. Subsequent results obtained revealed that the Blaine specific surface area is not directly related to the fresh grout properties. Grain size distribution and shape of lime particles and their aggregates in the water suspension are key parameters influencing the following fresh grout properties: fluidity, injectability, the mixture’s stability, and water retention capacity. However, the lime injection grouts’ mechanical strengths were higher in relation to an increase in the content of portlandite and the Blaine specific surface area of the dry hydrate.

USING TECHNICAL SULFUR AS A STRUCTURING ADDITIVE FOR MINERAL BINDERS BASED ON CALCIUM SULFATE

The article discusses physical and chemical characteristics of producing effective materials based on calcium sulfate dihydrate, the pretreated waste of man-made production being added at the stage of mixing the air binder. The high degree of consumption of exhaustible natural resources causes increased research activities in the field of application of industrial waste in construction. Using manmade waste, such as technical sulfur, as a modifier of the structure and properties of building materials is a significant step in solving environmental, resource, and economic problems. Industrial production of building materials today follows the principles of sustainable development and waste minimization by optimizing product formulations and reducing energy consumption required for their production. In addition, the improvement of quality and performance indicators of standardized products is relevant and sought-after. The need for efficient technologies for utilization of technical sulfur is due to large volumes of production and the environmental threat which accompanies the storage of its large volumes. Adding technical sulfur as a component of technological construction mixtures will create an alternative to the methods of utilization of this production waste. Physical and technical and physical and chemical properties of technical sulfur predetermine the possibility of its use, with certain additional treatment, as an effective modifier of the structure and properties of gypsum products. The results presented in the article prove the potential use of this production waste as an effective structure-forming additive, which has a positive effect on the physical and technical parameters of calcium sulfate-based materials.

The effect of pozzolan addition on the physical and mechanical properties of lime mortar

Hydrated lime, due to its life cycle (return to the natural form as a result of binding and hardening) shows a positive ecological aspect. The binder is often used in building materials based on plant components due to the high alkaline reaction and low diffusion resistance, as well as in mortars and plasters. However, it is an air binder with low strength parameters and the process of its binding and hardening is long-lasting. One of the ways to accelerate the binding processes and also to increase the strength of the binder is the use of additives in the form of pozzolanic materials which react with calcium hydroxide and form compounds with hydraulic properties. These are natural materials or industrial waste, so they do not affect the environmental impact of lime binder. The article presents the influence of the addition of pozzolan (three types) in various weight amounts, on the strength properties of mortars, their absorbability and capillary rise (presented as water absorption coefficient). The influence of pozzolan presence on workability of fresh mortars - their consistency was also checked.

Mechanisms of breakdown of the structure of glass cloth during impregnation with polymer binders

The basic sources of worsening of the quality indexes of insulating glass cloth and the requirements for the properties of the cloth and binder during impregnation were determined: short pile, gas inclusions, thermodynamic characteristics of binder and monofilament on the binder—monofilament, binder—air, and air—monofilament interface, internal stresses in the structure of the cloth, weave geometry, and position of monofilaments in the complex fibre.