Introduction. Expansion joints are an integral part of the design of a cement-concrete road surface, as they provide compensation for temperature and shrinkage deformations, preventing uncontrolled crack formation. Rational design of the distance between expansion joints is one of the key factors affecting the durability and load-bearing capacity of the road surface. Incorrect calculation of these parameters can lead to premature failure of the structure, a decrease in its operational reliability, and an increase in repair and maintenance costs [1 – 6].
This article considers the issue of improving approaches to calculating the distance between expansion joints in a cement-concrete surface based on the DSTU draft "Guidelines for the design of rigid road surfaces", which is currently being developed by the SE «NIDI» with the participation of the National Transport University. The proposed methods were developed taking into account the advanced domestic and international experience in designing highways with rigid road surfaces, analysis of current regulatory legal acts, building codes, scientific and technical literature, as well as modern road construction materials and technologies. Special attention is paid to the peculiarities of road and climatic regions of Ukraine, which allows adapting the methodology to real conditions of operation of the road surface.
Problem statement. Designing rigid road surfaces is a complex engineering task that requires accurate consideration of all operational factors, in particular, determining the optimal distance between expansion joints. The inconsistency of existing methods with real operating conditions can lead to premature destruction of the cement concrete surface, the appearance of uncontrolled cracks, and an increase in costs for repair and operational maintenance of highways.
A modern approach to design should unify and improve the methodology for calculating the distance between expansion joints, taking into account the physical and mechanical properties of cement concrete, temperature and humidity conditions, type and intensity of traffic load, and the characteristics of road and climatic regions of Ukraine. The determination of the relevant parameters should be carried out on the basis of reliable initial data, which will increase the durability of the road surface and ensure the efficient use of material and technical resources.
Therefore, there is an urgent need to develop an improved methodology that would meet modern requirements for road construction, contribute to increasing the operational reliability of cement concrete road surfaces, and ensure economically feasible use of resources.
Objective. The modern development of road construction requires constant improvement of approaches to the design of rigid road surfaces, in particular, the determination of optimal distances between expansion joints. Taking into account the latest scientific research, modern materials and innovative technologies allows to increase the durability and reliability of cement concrete pavement, reduce the risk of cracking and optimize the costs of repair and operational maintenance of highways.
The purpose of the work is to inform road specialists about the latest trends, methods and developments in the field of rigid road surface design, in particular, regarding the improvement of approaches to determining the rational distance between expansion joints of cement concrete road surfaces. The proposed solutions are aimed at increasing the efficiency of design solutions, adapting existing methods to modern operating conditions and ensuring economically justified use of material and technical resources.
Materials and methods. The study used a comprehensive approach based on the analysis of scientific and technical developments in the field of designing rigid road surfaces, as well as practical experience in its arrangement. In particular, the results of research conducted by the SE «NIDI» and the National Transport University, which are based on many years of experience in providing services in the field of road construction, were taken into account.
The methodological basis of the work is the analysis of current building codes and national standards of Ukraine, as well as their comparison with relevant foreign regulatory documents and technical literature. To ensure the comprehensiveness of the study, domestic and international experience gained during the design and arrangement of rigid road surfaces was taken into account.
Mathematical modeling methods were used to determine the optimal distances between expansion joints, assess the stress-strain state of cement concrete slabs and predict their behavior under various operating conditions. Analysis of the results allows us to substantiate improved approaches to design and implement effective solutions in road construction.
Results. As part of the study aimed at implementing modern methods for designing highways with rigid road surfaces, a DSTU project was developed, which contains updated recommendations for determining the distance between expansion joints in cement concrete pavement.
The proposed methodology takes into account various structural types of cement concrete road pavement, in particular:
- Jointed Plain Concrete Pavements (JPCP);
- Jointed Reinforced Concrete Pavements (JRCP);
- Continuously Reinforced Concrete Pavements (CRCP) if such a calculation is required;
- Roller Compacted Concrete Pavement (RCCP) if such a calculation is required.
Updated approaches to calculating the distance between expansion joints are based on modern scientific research, international experience and practical data, which allows increasing the durability of cement concrete pavement, reducing the risk of uncontrolled cracking, and improving the performance characteristics of road surface structures.
Conclusions. The proposed methodology for designing rigid road surfaces on highways improves existing approaches and establishes scientifically based requirements for calculating the distance between expansion joints. It is based on modern research, takes into account the design features of cement concrete road pavements, operating conditions and advanced world experience, which allows to increase the effectiveness of design solutions.
The use of this methodology will contribute to improving the operational characteristics of road surface structures, increasing their strength, resistance to loads and durability. This, in turn, will make it possible to reduce the risk of premature cracking, reduce the cost of repairing and maintaining the road surface, as well as ensure more rational use of material and technical resources in the field of road construction.
The implementation of an improved design methodology will contribute to improving the quality and reliability of cement concrete roads in Ukraine, which meets modern requirements for the development of road infrastructure and international standards.
