This research explores the innovative resilience and self-healing properties of engineered cementitious composites (ECC) reinforced with shape memory alloy (SMA) fibers, tailored for environments susceptible to saltinduced freeze-thaw damage from deicing salts, seawater, and saline soils. The study examines ECC composites enhanced with varying SMA fiber volumes 0 %, 0.5 %, 0.75 %, and 1 % and three fiber shapes linear, indented, and hook-shaped, with an additional sandblasting surface treatment. Systematic analyses of monotonic and cyclic flexural behavior, as well as self-healing efficacy, were performed across four distinct freeze-thaw cycles (0, 50, 100, and 150) within environments of fresh water and a 3.5 % NaCl solution. Digital Image Correlation (DIC) was employed to precisely monitor the self-healing performance. The results highlight substantial enhancements in SMA-ECC, particularly improved flexural strength by up to 35 %, 30 %, and 17 % for hook, indented, and linear fibers respectively in freshwater. These gains were slightly reduced under saltwater conditions to 32 %, 26 %, and 15 % respectively. Additionally, crack-closure efficiencies in significant self-healing with improvements of 45 %, 38 %, and 27 % for hook, indented, and linear fibers respectively. The Weibull probability distribution model was used to establish the damage evolution equation of the SMA-ECC in two freeze-thaw environments. The results of this study can serve as a reference for the development of freeze-thawresistant designs for SMA-ECC structures in future applications.

Soil stabilizers are environmentally friendly engineering materials that enable efficient utilization of local soil-water resources. The application of nano-modified stabilizers to reinforce loess can effectively enhance the microscopic interfacial structure and improve the macroscopic mechanical properties of soil. This study employed nano-SiO2 and nano-CaCO3 to modify cement-based soil stabilizers, investigating the enhancement mechanisms of nanomaterials on stabilizer performance through compressive and flexural strength tests combined with microscopic analyses, including SEM, XRD, and FT-IR. The key findings are as follows: (1) Comparative analysis of mortar specimen strength under identical conditions revealed that nano-SiO2 generally demonstrated superior mechanical enhancement compared to nano-CaCO3 across various curing ages (1-3% dosage). At 1% dosage, the compressive strength of both modified stabilizers increased with curing duration. Early-stage strength differences (3 days) remained below 3% but showed a significant divergence with prolonged curing: nano-SiO2 groups exhibited 10.3%, 11.3%, and 7.2% higher compressive strengths than nano-CaCO3 at 7, 14, and 28 days, respectively. (2) The strength enhancement effect of nano-SiO2 on MBER soil stabilizer followed a parabolic trend within 1-3% dosage range, peaking at 2.5% with over 15% strength improvement. (3) The exceptional performance of nano-SiO2 originates from its high reactivity and ultrafine particle characteristics, which induce nano-catalytic hydration effects and demonstrate strong pozzolanic activity. These properties accelerate hydration processes while promoting the formation of interlocking C-S-H gels and hexagonal prismatic AFt crystals, ultimately creating a robust three-dimensional network that optimizes interfacial structure and significantly enhances strength characteristics across curing periods. These findings provide scientific support for the performance optimization of soil stabilizers and their sustainable applications in eco-construction practices.

Despite its advantages, conventional soil-cement has limitations in terms of mechanical strength and durability, especially in environments with high humidity or high structural demands. The development of high-performance soil-cement (HPSC) presents significantly superior mechanical properties. The decentralized production of these panels has resulted in a cost reduction of more than 40%, making them an affordable alternative for low-income communities. Even so, providing technical support for the popularization of HPSC is crucial for the advancement of civil construction and to enable the expansion of affordable and sustainable housing for vulnerable communities. This study focuses on the development of a high-performance soil-cement panel, including its manufacturing process and the materials used. The panel was produced using Yellow Argisol soil, found locally in abundant quantities, modified with sand. Measurements of flexural strength and water absorption were carried out, together with a comparison of the strength of high-performance concrete (HPC) found in the literature. The developed panels present an average flexural strength of 6.71 MPa. Additionally, water absorption reached 5.99%, indicating the high performance of this material, which is comparable to high-performance concrete but more economical and sustainable. This contribution confirms the viability of transferring HPSC technology and highlights its social impact on civil construction.

This paper presents the results of experimental testing of adobe masonry assemblages to study their flexure and bond behaviors. The properties of soil and water absorption of adobe units also were investigated. The plasticity index of the soil was 7.56, which was higher than that reported for the adobe soil in a few regions of the world. The silt and clay contents of the soil also were higher than those of the soil used by researchers elsewhere. High water absorption of the adobe units (27.37%) indicated their low cohesion characteristic, which was evidenced by low bond strength. The flexural strength of the wallettes tested in a direction parallel to the bed joints was less than that of those tested perpendicular to the bed joints. The tensile bond strength determined by the bond wrench method was considerably smaller than the flexural strength of the wallettes. The observed flexural and bond strengths of the adobe masonry also were smaller than those reported in the literature.

In the surrounding rural region of Hawassa village houses are constructed by using soil, wood, teff straw, and water which is called chika in the local name, although its degradable materials prompt a shift to adobe brick for durability. Adobe brick, prevalent in rural locales, offers social, economic, and cultural advantages. However, its inherent flaws include brittleness, low compressive, and tensile strength, along with moisture sensitivity. This research aims to enhance the native soil attributes of Hawassa villagers by integrating sisal fiber for brick production. The investigation employed soil, water, and sisal fiber to create enhanced adobe bricks. A displacement controlled uniaxial testing machine was utilized to evaluate the compressive strength of the bricks. Findings indicated that a 0.9% sisal fiber inclusion achieved a maximum compressive strength of 13.44 MPa, outperforming conventional samples by 3.4 times, alongside a flexural strength of 0.097 MPa, exceeding conventional results by 3.34 times. The study includes a comparative analysis of mechanical properties and a cost evaluation between traditional and enhanced approaches.

The clay brick industry is facing significant challenges related to improving its physico-mechanical properties and durability performance of sustainable products. The current study aimed to investigate the effect of stabilizers (lime and cement) on the clay brick properties of three soils. The investigated soils were taken from different regions of Algeria. A series of laboratory experiments were carried out to examine the effect of lime and cement addition with different ratios of 2%, 4%, 6%, 8%, and 10%, on the mechanical properties. The assessment was based on compressive strength, flexural strength, total and capillary water absorption tests. The test results showed that the lime addition to soils A and B led to a significant increase in compressive strength (CS) by 47% and 101%, respectively. The highest values obtained were for the 8% ratio. The obtained gain in compressive strength soil C reached its maximum CS at 6% ratio, and the obtained gain was 44%. However, for cement addition, the highest CS values were obtained at the 10% ratio for all studied soils. The observed gains in compressive strength for soils A, B, and C were 24%, 15%, and 33%, respectively. Flexural strength (FS) followed a similar trend, with lime addition improving (FS) by up to 400% for soil A at an 8% ratio. Cement addition also enhanced (FS), with the highest improvement of 103%, which was observed for soil A at a 10% ratio. It was also observed that lime addition significantly decreased the total absorption by up to 36% at an 8% ratio for soils A and B, and at 6% for soil C. In contrast, the total absorption decreased uniformly with the cement addition up to the 10% ratio. The lowest absorption observed at a 10% ratio was 11.95%. Lime addition also decreased the capillary absorption of clay bricks, and the lowest value was observed at an 8% ratio for both soils (A and B) and 6% for soil C. The CA values decreased by approximately 24% for soils A and B and 14% for soil C. In the case of cement addition, it was noted that the capillary absorption had the same pattern as the total absorption. The percentage decreases in CA were 41%, 40%, and 38% for soils A, B, and C, respectively. These results indicate that the enhancement of clay brick was observed for lime addition ranging from 2% to 8%. Therefore, good mechanical strengths were obtained at a 10% cement ratio.

This study examines the effectiveness of the bi-stabilization of clay soils using cane molasses and coconut fiber, focusing on improving the geotechnical and mechanical properties of clay. The performance of the two stabilizers, both individually and in combination for bistabilization, was assessed. The geotechnical properties were determined through sieve analysis, Proctor tests, and Atterberg limit methods, while the mechanical properties were measured using a hydraulic press. The results showed that cane molasses reduced plasticity, enhanced soil cohesion, and increased dry density with molasses content. The Atterberg limits (liquid limit, plastic limit, and consistency index) were maximized at a 4% molasses content, with respective increases of 9.28%, 44.80%, and 37.9% compared to clay without molasses (CB). Coconut fiber improved the flexural strength by 361.9% for CF1, whereas molasses improved the compressive strength by 12.24% compared to plain clay. Bi-stabilization allowed for a maximum improvement in flexural strength of 509.52% compared to CB, 49.42% compared to molasses-stabilized clay bricks (CSM), and 31.96% compared to clay composites with coconut fiber (CF). The compressive strength improved by 22.54% compared with CB, 9.21% compared with CSM8, and 14.94% compared with CF 1/2. In summary, bi-stabilization with sugarcane molasses and coconut fiber provided enhanced performance compared with their individual use.

Fluidized solidified soil ( FSS ) is a cement-based engineering matergood working performance and mechanical properties. Based on fi xed cement and desulphurisation gypsum ( DG ) , fl y ash ( FA ) and ground granulated blast furnace slag ( GGBS ) were added as admixtures to the construction slurry to prepare three types of FSS: namely cement-GGBS-DG FSS ( CGD-FSS ) , cement-FA-GGBS-DG FSS ( CFGD-FSS ) , and cement-FA-DG FSS ( CFD-FSS ) . Considering 7 d, 14 d, and 28 d three curing times, compressive, fl exural, scanning electron microscopy ( SEM ) , and x-ray diffraction ( XRD ) analyses were conducted to explore the time-dependent mechanical properties and microscopic characterisation of FSS. The mechanical test showed that CFGD-FSS doped with FA and GGBS had better fl uidity, compressive strength, and fl exural strength than CGD-FSS doped with FA alone and CFD-FSS doped with GGBS. The CFGD-FSS specimen with a cement:FA:GGBS:DG ratio of 30: 10:40:20 in the curing agent had the best mechanical properties, i.e., the CFGD01 specimens. It has fl uidity of 189 mm, compressive strength of 671 kPa, and fl exural strength of 221 kPa with a 28d curing time, which can meet the working requirements of FSS for fi lling narrow engineering spaces. And compared with other specimens, it has the shortest setting time, which can effectively shorten the construction period. Microscopic analysis showed that a large number of hydration products, such as calcium silicate hydrate, calcium aluminate hydrate, and ettringite ( Aft ) , were well-formed in the FSS, resulting in good mechanical properties, especially for the CFGD-01 specimens. Finally, two empirical models were established to describe the compressive strength-porosity and fl exural strength-porosity relationships. Moreover, the investigated data agreed well with the modelling results.

Conservation of historical and vernacular architecture often involves the use of traditional materials such as unfired clay, which require precise mechanical characterization for effective preservation strategies. Experimental analysis for determining the compressive and flexural strengths of these materials can be time-consuming and costly. To address this, the present study aims to streamline the process by leveraging artificial neural networks (ANN). Two ANNs were developed and trained using experimental data from laboratory tests on unfired clay matrices. The trained models provided accurate predictions of mechanical properties, achieving an error rate of less than 1% for test values. These results demonstrate the potential of ANNs as efficient tools for predicting the mechanical behavior of unfired clay, offering significant time and resource savings in the conservationfield. This approach enables more effective preservation and restoration of structures that utilize unfired clay, supporting efforts to maintain architectural heritage.

Thailand is situated in the heart of Southeast Asia and is classified as having a tropical climate with high rainfall frequency and occurrence of floods. The weakening effect of water on laterite soil has led to different road damages such as potholes. Under these adverse environmental conditions, heavy traffic could also result in the formation of cracks and poor performance of roads. This study investigates the effects of Rice Husk Ash (RHA), Lime (L), and Coir Fiber (CF) as soil reinforcement material on the engineering properties of laterite soil. Several tests were conducted including the Unconfined Compressive Strength (UCS) test, three-point bending flexural strength, direct shear test, completely soaked durability test (to mimic flood conditions), X-ray Fluorescence (XRF), and Scanning Electron Microscopy (SEM) to observe the micro-structural changes of stabilized soil. The laterite soil was replaced by 10%, and 20% of RHA, 1% of CF, and 8% of L. The samples were cured for 7, 28, and 56 days before conducting the tests. The 20RHA8L mix designs showed the highest UCS value after 56 days curing period. In terms of the durability test results, the 20RHA8L mix design also exhibited the lowest reduction in compressive strength (3.8% drop) after undergoing 6 wetting-drying cycles. According to flexural strength, the 20RHA1CF8L (20%RHA, 1%CF, 8%L) mix design indicated a tenfold increase in flexural strength compared to the natural laterite soil after 28 days of curing. Based on the findings of this research, CF and RHA are beneficial for earth structures such as embankments and road layers that are subjected to significant tensile stresses. These waste materials can also reduce the brittleness of lime-stabilized soil.