The search for alternative material sources to conventional ones has had a significant impact on the construction sector today, driven by the implementation of sustainable development policies on a global scale. Alternative cementitious materials, such as agricultural industry by-products, have been introduced to ensure the efficient use of renewable natural resources while promoting a balance between the technical and economic aspects of infrastructure projects. This article provides an overview of research conducted on the use of pozzolans derived from agro-industrial by-products, such as rice husk ash (RHA), palm oil fuel ash (POFA), and sugarcane bagasse ash (SCBA), which have a high content of amorphous silica. This silica reacts with calcium hydroxide during the hydration process of Portland cement, leading to the production of calcium silicate hydrate (C-S-H) gel with cementitious properties. Investigations have explored the improvements these pozzolans provide in terms of compressive, flexural, and tensile strength in concretes where conventional Portland cement has been partially replaced by these materials. The influence of temperature and grinding processes used in their preparation was also determined, with optimal temperatures for obtaining amorphous silica ranging between 600 °C and 700 °C. Additionally, the optimal replacement levels for enhancing the mechanical properties of concrete were found to range between 10 % and 20 %.

Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses), it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, which helps prevent moisture formation retaining its strength due to the greater adherence shown with dry polystyrene. It was more flexible, which makes it less vulnerable to cracking walls due to soil displacements. Furthermore, it is economical, because it uses recyclable material and has properties that prevent deterioration increasing its useful life. We recommend the use of the fully dry EP under a dry environment to obtain the best properties of brick.

Bicycle use has become more important today, but more information and planning models are needed to implement bike lanes that encourage cycling. This study aimed to develop a methodology to predict the speed a cyclist can reach in an urban environment and to provide information for planning cycling infrastructure. The methodology consisted of obtaining GPS data on longitude, latitude, elevation, and time from a smartphone of two groups of cyclists to calculate the speeds and slopes through a model based on a recurrent short-term memory (LSTM) type neural network. The model was trained on 70% of the dataset, with the remaining 30% used for validation and varying training epochs (100, 200, 300, and 600). The effectiveness of recurrent neural networks in predicting the speed of a cyclist in an urban environment is shown with determination coefficients from 0.77 to 0.96. Average cyclist speeds ranged from 6.1 to 20.62 km/h. This provides a new methodology that offers valuable information for various applications in urban transportation and bicycle line planning. A limitation can be the variability in GPS device accuracy, which could affect speed measurements and the generalizability of the findings.

Soil’s consolidation is a geotechnical problem resulting from a stress-transfer process that initiates when the load is applied to the water contained in the soil, producing a reduction in pore water pressure and rearranging the solid particles, and thus causing a decrease in soil volume. Therefore, consolidation is a coupled flow–mechanical problem. Coupled models have been developed to simulate this phenomenon while considering different theories, providing consistent results. This paper presents an elastoplastic coupled model of consolidation under Terzaghi’s effective stress formulated using the equations of transient flow, balance moment, motion, and the critical state model that considered elastoplastic strains. The coupled model algorithm provided fast and easy results due to its flexibility, as it allowed combinations in loading and boundary conditions. Additionally, it considered the external/internal water flow as an inflow or outflow, which modified the pore water pressure and produced changes in the horizontal and vertical displacements. The numerical results obtained showed an appropriate behavior of the consolidation phenomenon, as well as the evolution of the vertical $U_y$ and horizontal $U_x$ displacements, water pressure $p_w$, volumetric ${\epsilon }_v$ and deviatoric ${\epsilon }_q$ strain, mean ${\sigma }_p$ and deviatoric ${\sigma }_q$ stress, volumetric variation $∆{\epsilon }_v$, and elastic/plastic behavior of the finite elements while considering the yield surface of the critical state.

The volumetric change within soils containing expanding clays depends upon their spatial ordering and their mineralogy. So this work studies the spatial microstructural ordering and mineralogy of different expanding clays in order to correlate them with some of their geotechnical properties (plasticity, classification, and expansion). The clay microstructure was obtained using X‐ray diffraction, and sweeping electronic microscopy. Physical characterization includes pH analysis. Clays with greater swelling (12.1–14.6% expansion) present greater agglomeration (gathering) (20–50 microns) in a flocculated structure that mainly contained sodic montmorillonite with 14–22 Å openings and 8.28 average pH, which indicates high electron concentrations with border‐face interactions. Clays with the least expansion (7.6%) present lower agglomerations (5–10 microns) with face‐to‐face contacts within a dispersed structure that mainly contained calcium montmorillonite with openings lower than 15 Å and pH 7.56, which indicates a low electron concentration and face‐to‐face interaction. Major clay expansion corresponds to a greater size agglomerates, greater opening between particles, and greater pH presenting border‐face and face‐to‐face interactions of a flocculent structure. Yet, the soils with lower expansion only present face‐to‐face interactions corresponding to a dispersed structure.