Old structures that are made of adobe or brick walls are usually unreinforced and not designed for lateral forces. In-plane loads applied to unreinforced masonry walls (URM) are the usual cause of damage and failure of old buildings. In this research, small unreinforced brick masonry wallettes, 350 mm × 350 mm and 50 mm in thickness, are strengthened using bamboo fiber textile and plastered to the face of the walls using short bamboo fiber-reinforced geopolymer mortar. The wallettes are subjected to diagonal shear tests as described by ASTM E519 to investigate the in-plane shear performance of the strengthening method. The performances of 5 wallettes strengthened on one-side with mortar only, 5 wallettes on both-sides with mortar only, 5 wallettes with textile plastered on one-side only, and another 5 wallettes with textile plastered on both-sides, are compared to 5 control specimens without any strengthening. It is observed that the wallettes strengthened on one side and both sides with textile yield an increase in shear of about 24% and 35% in average, respectively. Failure modes show that the usual failure for URM is running bond failure and for strengthened URM is columnar failure. The implications of the results can be used in developing textile-reinforced geopolymer mortar systems to strengthen URM walls.

Geopolymer, a sustainable alternative to ordinary Portland cement (OPC), offers reduced embodied energy, lower carbon emissions, enhanced durability, eco-compatibility, and waste valorization potential. In confining structural members, geopolymer still has limitations with respect to its brittleness and other properties. Enhancing the properties of geopolymer by adding banana fibers (BF) and fly ash (FA) to form banana geotextile-reinforced geopolymer mortar (BGT-RGM) as confining material, is investigated in this experimental study. BGT-RGM is a textile-reinforced mortar with varying thickness of BF-reinforced geopolymer mortar (BFRGM) through NaOH-treated 10 mm BFs and 2 mm banana geotextile (BGT) having varied grid spacings. To develop BGT-RGM, the physical, mechanical, and chemical properties of the BFs were determined, while BFRGMs were evaluated for compressive and dog-bone tensile strengths, workability, scanning electron microscopy (SEM) imaging, and thermogravimetric analysis (TGA). The BGT-RGM-confined and unconfined concrete were evaluated, and the strength variations were imparted by the confinement as reflected on the stress-strain curves. The local crack formation mode of failure was also determined through crack patterns during an axial load test. The BGT-RGM with 20 mm thickness of BFRGM with 15 mm and 20 mm geotextile grid spacings, exhibited 33.3% and 33.1% increases in strength, respectively. Future investigations towards the development and application of BGT-RGM are also discussed.

Textile-reinforced mortar (TRM) is an effective method for confining concrete elements to elevate the axial load resistance and upgrade the overall performance of concrete. TRM is a promising alternative to carbon-fiber-reinforced polymers (CFRP) which are commonly used to strengthen concrete and are known to be expensive since they require a huge amount of energy in processing these materials. Green technologies can be applied in this process, following the same TRM principles of confinement, replacing conventional cement or epoxy-based mortars and synthetic textiles towards sustainable concrete strengthening technology. This is through the utilization of a geopolymer mortar reinforced with short banana fibers (BF) and long BFs as textiles. Geopolymer mortar presented in this paper is composed of fly ash and silica fume as the binder, sand as the filler, sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) as the activator and BFs as the reinforcement and textile. Geopolymerization generates significantly less carbon dioxide (CO₂) while BFs are known for having attractive mechanical properties, are cost effective and abundant in nature, and thus the use of this fiber will significantly minimize the huge waste produced from banana plantations after a one-time fruit harvest. The geotextile or geogrid used to wrap the concrete cylinder samples is made up of 2 mm-long BF yarns with weights ranging from 150 to 450 grams per square meter that varies with grid sizes from 10 mm, 15 mm to 25 mm for both orthogonal directions considering the lightweight characteristic of BFs. Twelve TRM designs were used to strengthen the concrete cylinders with three samples each. TRM design parameters vary in the thicknesses of the geopolymer mortar covering and the size of the geotextile grids. Eighteen of the geotextiles used were coated with a polymer to protect the fibers while the other eighteen geotextiles remained uncoated. A total of thirty-nine concrete cylinders with 150 mm base diameter and 300 mm height cured within 28 days were prepared, for which 36 cylinders were confined with green TRM with different parameters while three of the plain concrete cylinders served as the control specimens. This is to maximize the investigation on the potential of green TRM in confining concrete and to determine the variations in compressive strengths and mode of failures of confined and unconfined concrete specimens. Results highlighted notable enhancement in the mechanical properties of the modified plain concrete after 28 days of TRM curing using a universal testing machine (UTM). Likewise, a confinement theory of the optimum TRM design was modeled mathematically to evaluate the effects of concrete confinement and overall load carrying capacity enhancement gained from additional strength transferred by the TRM to the concrete element.

Dyes for security markings play a pivotal role in safeguarding the integrity of products across various fields, such as textiles, pharmaceuticals, food, and manufacturing among others. However, most commercial dyes used as security markings are costly and may contain toxic and harmful substances that pose a risk to human health. Curcumin, a natural phenolic compound found in turmeric, possesses distinct photoluminescent properties alongside its vibrant yellow color, making it a potential candidate material for authentication applications. This study demonstrates a cost-effective and eco-friendly approach to develop enhanced photoluminescent emissions from curcumin dyes for textile authentication. Curcumin was extracted from C. longa using sonication-assisted-solvent extraction method. The extract was dip-coated and dyed into the textile substrates. Chitosan was introduced as a post-mordanting agent to stabilize the curcumin and as a co-sensitizer. Co-sensitization of curcumin with chitosan triggers energy transfer to enhance its luminescent intensity. The UV-visible absorption peak at 424 nm is associated with the characteristic absorption of curcumin. The photoluminescence measurements showed a broad emission peaking at 545 nm with significant enhancement attributed to the energy transfer induced by chitosan, thus showing great potential as a naturally derived photoluminescent dye for authentication applications.

Bamboo textile fiber (BTF) is a renewable alternative to synthetic textiles in textile-reinforced mortar (TRM), but the effects of yarn architecture and coating on its tensile and bond behavior are not well established. This study tested four BTF-reinforced TRM configurations with a 15 × 15 mm grid: textiles woven from single-ply (SP) and two-ply (DP) yarns, each in dry and epoxy-coated (SPI, DPI) conditions. Twenty direct tensile coupons and twenty textile–mortar bond specimens bonded to concrete substrates were tested under displacement control. The effects of ply configuration, coating and their interaction were evaluated by two-way ANOVA, and the coated yarn surface was examined by scanning electron microscopy. Epoxy coating significantly increased peak strain and toughness (p < 0.001) and peak tensile stress (p = 0.008), with the largest effect for the two-ply textile, for which toughness increased from 0.09 to 0.54 MJ/m³ and peak tensile stress from 16.11 to 28.36 MPa. Ply configuration (p < 0.001) and coating (p = 0.018) both significantly increased the peak textile-normalized bond stress, from 3.52 MPa (SP) to 9.65 MPa (DPI), with no significant interaction; all bond specimens failed by textile rupture, so these values are lower bounds. DPI gave the highest peak strain, toughness and peak bond stress, supporting its selection for structural-level validation.