In the ever-evolving world of construction materials, a groundbreaking study led by Irina V. Erofeeva from the National Research Moscow State University of Civil Engineering is shedding new light on how to enhance the performance of concrete structures. Published in the journal ‘Нанотехнологии в строительстве’ (translated to English as ‘Nanotechnologies in Construction’), Erofeeva’s research delves into the deformation and fracture processes of cement paste and powder-activated concrete, offering insights that could revolutionize the energy sector and beyond.
Concrete, the backbone of modern infrastructure, is subjected to various loads during its operational life, leading to deformation and eventual destruction. Erofeeva’s study demonstrates that the strength and elastic-plastic properties of modern concretes can be finely tuned using superplasticizers, nanoadditives, fillers, and fine aggregates. “By understanding and controlling these factors, we can significantly improve the crack resistance and overall performance of concrete structures,” Erofeeva explains.
The research focuses on the stress-strain diagrams of concrete, which are crucial for determining the key characteristics of concrete deformation processes. Erofeeva and her team obtained complete concrete stress-strain diagrams with an extended descending section by loading specimens at a constant, decaying strain rate. This method resulted in a smooth decrease in stress in the specimen along the descending section, providing a more accurate representation of the material’s behavior under load.
One of the most significant findings of the study is the impact of the water-to-cement (W/C) ratio on the material’s behavior. Increasing the W/C ratio from 0.267 to 0.350 resulted in more elastic behavior of the material under load, a significant elongation of the descending branch of the full equilibrium stress-strain diagram of hardened cement paste, and a change in the failure mechanism of the material. “This finding could have profound implications for the design and construction of concrete structures, particularly in the energy sector where structures are often subjected to high loads and extreme conditions,” Erofeeva notes.
The study also examined the influence of various additives on the deformation and fracture processes of concrete. The addition of the carboxylate superplasticizer “Melflux 1641F” was found to make the deformation pattern of the specimen under load closer to that of cement paste obtained using normal-thickness cement paste, albeit with a shorter descending branch, indicating more brittle behavior of the specimen. The use of finely dispersed quartz also affected the nature of the deformation of the samples, increasing their elasticity but decreasing the magnitude of ultimate deformations.
The commercial implications of this research are vast. By optimizing the component contents of cement stone and powder-activated concrete, crack resistance parameters can be significantly increased, leading to more durable and reliable structures. This is particularly relevant for the energy sector, where the integrity of structures is paramount. “Our findings could lead to the development of new, high-performance concretes that are better suited to the demanding conditions of the energy sector,” Erofeeva says.
The research also provides a method for approximating the curves of the complete equilibrium diagrams in sections by simple linear and quadratic functions or represented by a cubic polynomial. This could simplify the analysis and design process, making it more efficient and accurate.
As the construction industry continues to evolve, the insights gained from this research could shape future developments in the field. By understanding and controlling the deformation and fracture processes of concrete, we can create structures that are not only stronger and more durable but also more sustainable and efficient. This is a significant step forward in our quest to build a better, more resilient world.