Introduction The use of geotextiles is now well established in the field of civil engineering, particularly in geotechnics, where they serve a range of functions including drainage, filtration, separation, reinforcement, protection, and erosion control. For over three decades, these materials have played a key role in the design and long-term performance of infrastructure. The development of geotextiles made from natural plant fibers, especially those derived from kenaf, represents a promising advancement that offers both economic and environmental benefits. This study aims to evaluate the mechanical and hydraulic properties of woven geotextiles made from kenaf fibers sourced from Nérékourosso, as well as their effectiveness in reinforcing road foundation layers. Methods Two types of geotextiles were produced by weaving, with mesh openings of 0 mm and 5 mm, respectively. Mechanical characterization tests were carried out, along with static puncture resistance and normal-to-plane permeability tests. CBR load-bearing tests were performed to evaluate reinforcement efficiency depending on the geotextile’s position in the foundation layer. Mechanical tests showed higher tensile strength in the cross direction for the geotextile with no mesh opening (17.19 kN/m) compared to the 5 mm mesh type (2.90 kN/m). Results The closed-mesh geotextile withstood a maximum puncture load of 1170 N, versus 540 N for the open-mesh variant. The 0 mm mesh geotextile exhibited a surface flow rate of 2200 L/min/m 2 . CBR tests indicated better performance for the 5 mm mesh geotextile, especially when placed at mid-height within the reinforced layer. Discussion These results suggest that while the closed-mesh geotextile offers superior intrinsic mechanical properties due to its dense structure, the open-mesh variant performs better in soil reinforcement applications, likely because its structure allows better interaction with surrounding materials and more effective stress distribution. Conclusion Kenaf-based woven geotextiles show promising potential for road foundation reinforcement, with mesh configuration significantly influencing performance.

Flexible pavements, whose surface layers are made from hot mix asphalt, may show rutting in some of these infrastructures during the first months of life.In the city of Ouagadougou, this rutting phenomenon is sometimes observed.The objective of this article is to quantify the thermal response of the wearing course of national roads 1 and 2, when they are subjected to the braking of heavy trucks of 13 tons and 20 tons per axle.The meteorological conditions retained are those of the Burkinabe climate.The evaluation of the temperature was carried out by numerical simulation using the Comsol Multiphysics 5.2 software.This study showed that the thermal response of the pavement to the combined effects of surface temperature, overloading by a 20 tons heavy truck and braking during a heat wave increase in pavement surface temperature ranging from 1.09% for National Road 1 to 0.91% for National Road 2, particularly in the braking zone.This made it possible to establish the diagnosis according to which the nature of the bitumen used on the wearing course can reduce rigidity modulus.In predictive terms, they allowed us to deduce that an under-dimensioning of the wearing course, even if the bitumen was used is adequate.

The waters of the torrential rains in the city of Ouagadougou lead to the appearance or amplification of damage to the surface of asphalt pavements during the rainy season. Road infrastructure maintenance campaigns follow one another almost every rainy season to fill potholes and cracks observed on the pavements. Several hypotheses can be put forward as to the origin of the action of water on the surface of pavements: the pressure of runoff water, infiltration, thermal expansion during the rainy episode, etc. These various reasons reveal the need to take rainwater into account when designing pavements. A previous study on the effect of heat waves on pavement design made some recommendations for better design. It has raised the interest to observe the impact of rain on pavement deformability. The objective of this article is to estimate, as a first approach, the effect of tropical rains on the Thermomechanical behaviour of bituminous pavements formulated with pure grade 35/50 bitumen and grade 10/65 modified bitumen without trafic. The properties of the road materials and the data from the statistical treatment of rainfall in the city of Ouagadougou were determined. The software based on the finite element method was used to model the phenomena coupling the meteorological conditions to the mechanical structure of the pavement for the quantification of hygrothermal and mechanical deformations. The bituminous pavements studied were subjected to maximum rainfall intensities of 53.06 mm/h, and 99 mm/h with respective frequencies of occurrence of 2 years and 15 years. The comparison of the temperature profiles at the surface of the studied pavements, allowed to highlight the viscous character of the asphalt subjected (35/50 bitumen and grade 10/65 modified bitumen) to the rains of maximum intensity of 99 mm/h. The maximum deformations simulated during these rains are about 1.2 times greater in the wearing course than in the base course, which does not disrupt the classical order of temperature evolution in the different pavement layers under dry tropical conditions. These deformations obtained also respect the admissibility criteria in terms of pavement design for T2 trafic (151 to 300 Heavy Truck/day). This study could be expanded to include the permeability of bituminous surfaces and runoff phenomena that could provide information on the origin of the observed deterioration.

Current pavement design methods do not allow for the reduction of early deformation of the surface layers of bituminous pavements in the city of Ouagadougou. Weather conditions combined with traffic, particularly during heat waves, are factors. The temperature at the surface of the bituminous pavement can reach 62˚C but the complex modulus associated with this temperature is not taken into account in the design, hence the interest in proposing laws of dependence of the complex moduli is taken into account in the maximum temperatures of the pavement surface. The objective of this paper is to propose an experimental method to determine the temperature dependence of the complex moduli of asphalt mixes for temperatures between 40˚C and 70˚C. This experimental method consists of performing axial compression tests on cylindrical asphalt specimens. It was applied to three different formulas of bituminous mixes, intended for the wearing course, obtained from mixes of crushed granites, granular classes 6/10, 4/6 and 0/4, pure bitumens of grade 50/70, 35/50 and modified bitumen of grade 10/65. The comparative study of the experimental results obtained with the results of a semi-empirical methodology revealed a root mean square deviation from the mean of between 6.58% and 14.8% of the norms of the complex moduli (modulus of rigidity) of the asphalt mixes for a fixed frequency of solicitations of 10 Hz. The consistency of these results with data from the literature led to the initial conclusion that asphalt mixes formulated with 35/50 and 10/65 bitumen would have better compressive strength than those formulated with 50/70 bitumen, for exposure temperatures between 40˚C and 70˚C. This experimental approach could be an alternative to the complex modulus test for determining the modulus of rigidity for design purposes under real pavement exposure conditions in the city of Ouagadougou during heat waves.

: The bituminous pavements of the city of Ouagadougou (Burkina Faso) are made using old design methods which take into account the climate from the notion of equivalent temperature. Thus an equivalent temperature of 30 °C is often used for the design of bituminous pavements. The observation that has been made is that this temperature does not currently make it possible to reduce the problems of early degradation of the pavements linked to meteorological fluctuations. The objective of this article is to propose a numerical approach for determining the equivalent temperature from temperature measurements taken at the surface of the pavement. This approach consists in jointly using the Alizé-Lcpc sizing software and the Comsol Multiphysics software using the finite element method. For a four-layer bituminous pavement, located at 12.38° North and 1.48° West, in Ouagadougou, consisting of a surface course of bituminous concrete of 8 cm and a base course of gravel bitumen of 16 cm, an equivalent temperature of 35 °C was obtained.

The purpose of this article is to propose a two-dimensional (2D) model in finite element of distribution of the temperatures and deformations in extreme weather conditions of Burkina Faso (heat wave, heavy showers) using the software COMSOL Multiphysics. This model takes into account the hourly weather conditions (solar radiation, air temperature, air humidity, dew temperature, wind speed) as well as the temperature dependence of the mechanical parameters (elastic modulus, poisson ratio) of the asphalt pavement materials.The obtained results show that it’s possible to identify, for periods of the day, the existence of nonlinear and permanent deformations at the level of the superficial layers of the pavement. The meteorological factor proved to be more than decisive in the choice of bitumen used for the realization of asphalt pavement in tropical zones. ARTICLE HISTORY Received 19-11-2019 Revised 12-02-2020 Accepted 20-02-2020 Published 21-04-2020