workability

The growing global problem of waste tire disposal is prompting the quest for environmentally friendly rubber recycling solutions to support the principles of a circular economy. The development of rubber concrete is a promising aspect. The review highlights the impact of using waste tire rubber in concrete, assesses the advantages and limitations for optimizing material characteristics, as well as environmental benefits. Results of the role of rubber content, size, and additives on the workability, strength, dynamic properties, and durability of rubber concrete are presented.

The article analyzes the experience of using Portland limestone cement for the production of ready-mixed concretes. It is shown that polycarboxylate superplasticizers (PCE) play a decisive role in providing required technological and construction-technical properties of concrete. The data show that the most effective PCEs for maintaining the workability of the concrete mixture over time and obtaining the required strength class of concrete are РСЕ based on modified acrylic polymers.

The beginnings of warm mix asphalt are connected with the use of foamed asphalt in the ‘60s of the last century. Asphalt foaming occurs by contact with water or water steam that can be entered mechanically or under pressure. The foaming effect can be also obtained by the adding of zeolite to the asphalt mixture which causes the lower viscosity of the asphalt, better workability and adhesiveness of the mixture to the aggregate in lower temperatures. Presently, synthetic zeolites Aspha-Min and Advera are used for reducing the processing temperature.