Evaluation of the elastic modulus of pavement layers using different types of neural networks models

Introduction. This paper studies the capability of different types of artificial neural networks (ANN) to predict the modulus of elasticity of pavement layers for flexible asphalt pavement under operating conditions. The falling weight deflectometer (FWD) was selected to simulate the dynamic traffic loads and measure the flexural bowls on the road surface to obtain the database of ANN models.Materials and Methods. Artificial networks types (the feedforward backpropagation, layer-recurrent, cascade back- propagation, and Elman backpropagation) are developed to define the optimal ANN model using Matlab software. To appreciate the efficiency of every model, we used the constructed ANN models for predicting the elastic modulus values for 25 new pavement sections that were not used in the process of training, validation, or testing to ensure its suitability. The efficiency measures such as mean absolute error (MAE), the coefficient of multiple determinations R2, Root Mean Square Error (RMSE), Mean Absolute Percent Error (MAPE) values were obtained for all models results.Results. Based on the performance parameters, it was concluded that among these algorithms, the feed-forward model has a better performance compared to the other three ANN types. The results of the best four models were compared to each other and to the actual data obtained to determine the best method.Discussion and Conclusions. The differences between the results of the four best models for the four types of algorithms used were very small, as they showed the closeness between them and the actual values. The research results confirm the possibility of ANN-based models to evaluate the elastic modulus of pavement layers speedily and reliably for using it in the structural assessment of (NDT) flexible pavement data at the appropriate time.

Effect Of Resilient Modulus on Permanent Deformations Using VESYS 5W Program

Due to high temperatures and increased traffic loads, most of Iraq’s streets suffer from permanent distortion problems, especially in streets where there are checkpoints, therefore, there are needs for reports and researches specialized in improving the pavement layers and increasing their resistance to temperatures and high traffic loads to reduce the rut depth. In this research, the VESYS 5W program was used to find a potential value for rut depth, where ordinary asphalt mixes and improved asphalt mixes were used using SBS polymer at 4% by weight of asphalt were it is evaluated according to different properties of these mixture and the resilient modulus one of these properties for it is importance. The results showed that when the value of the resilient modulus increases, the rut depth decreases, as the rut depth was reduced by 42.5% for the surface layer and 73% for the base layer

Easy Way To Determine The Feasibility Of Coarse Aggregate On All Pavement Layers Using The Los Angeles Tatonas TA-700 Machine

The use of coarse aggregate with poor quality can cause bumpy roads, cracked roads, potholes, and others. Coarse aggregate wear is an indicator of the aggregate resistance index against friction with other objects. Any aggregate to be used in a pavement mix must meet the wear requirements. Low wear causes the aggregate to be easily crushed when exposed to friction and has an impact on a low level of stability. The purpose of this research is to determine the feasibility of coarse aggregate in Kedak Village, Kediri. One of the feasibility of coarse aggregate is reviewed based on wear with abrasion testing. This research was conducted by using an abrasion test using the Los Angeles TA-700 machine and SNI 2417:2008 as a reference. The specimens were taken at random and met the criteria for passing the number 3/4 sieve and stuck on the 2500 gram sieve number 1/2 and the aggregate that passed the 1/2 sieve was stuck on the 3/8 sieve as much as 2500 grams. The results obtained stated that the average wear of the abrasion test was 26.6%. Based on these results, the aggregate can be said to be feasible because it does not exceed 40% in accordance with the provisions of the 2018 Binamarga General Specifications. So that coarse aggregate from Kedak Village, Kediri can be used for all mixtures of road pavement layers.

Sustainable Materials: A Review of Recycled Concrete Aggregate Utilization as Pavement Material

In this paper, a comprehensive literature review was conducted on the utilization of recycled concrete aggregate (RCA), which is the dominant construction and demolition waste material, in base and subbase layers and its comparison with natural aggregate (NA). The effects of crushing on the particles as a result of the compaction on the resilient modulus, permanent deformation, and California Bearing Ratio are analyzed. The paper also contains the NA consumption and waste disposal policies of different countries, RCA standards, and the environmental-economic reasons for its use. This literature review mainly focuses on pavement layers as this is the main application of RCA in the use of recycled materials. Developing integrated construction and demolition waste management will help achieve the primary goal of preventing and reducing the generation of these wastes, both locally and globally. In this way, not only is the main purpose of preventing the increase in the production of construction and demolition waste achieved, but also the reuse and recycling of the waste materials produced are encouraged. Results show that RCA has equivalent or better performance than virgin aggregate for almost any application with proper care and process control, and can be used in unbound pavement layers or other applications requiring compaction. But it is always recommended that its mechanical properties and durability performance be evaluated with full-scale tests before use. The information provided will be useful for contractors and engineers to evaluate alternative solutions and to explore the rational use of such sustainable materials in applications.