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Glass Fibre Reinforced Polymer (GFRP) bars and Alkali Activated Cement (AAC) concrete are promising materials for replacing steel bars and ordinary Portland cement concrete. These materials can provide a solution to the associated corrosion and environmental issues. However, no design recommendations are available on splicing of GFRP bars in AAC concrete. This may be mainly due to insufficient data that would guide such recommendations. In this paper, the results of testing beams with spliced bars are presented mainly from consideration of the bond property between the spliced GFRP bars and the AAC concrete. The effects of splice length, compressive strength of concrete, and stirrup confinement on the bond behaviour are investigated. Ultimate moment capacity, failure modes, cracking pattern, and strain values in the bars have been determined and used in the analysis. A three-dimensional finite element model (FEM) was then developed. The FEM results show that the model accurately reproduces the experimental behaviour of splice tests with regard to load-deflection curves and failure modes. The reported results and numerical analysis are intended for understanding distribution of tensile and bond stresses in GFRP reinforced AAC concrete. These distributions were observed to be dependent on the applied load. [ABSTRACT FROM AUTHOR]

• Compaction improves splitting resistance of vertically cast specimens. • Top-cast specimens have a lower splitting resistance than bottom-cast specimens. • Higher splitting stress is generated orthogonal to the plane of the textile. • The main cause of splitting failure is the fiber strand's varying cross-section. • Bond distribution depends on the cross-section variation along the fiber strand. Textile-reinforced concrete is an innovative combination of high-performance fine-grained concrete and textile reinforcements. This combination allows the production of thin, efficient, and durable structural elements. Impregnation is commonly used to improve the textile's mechanical performance. When stiff impregnation materials are used, a fiber strand with high transverse stiffness is formed. Textile-reinforced concrete structures with such fiber strands are prone to splitting failures. This paper investigates splitting failure in textile reinforced concrete experimentally and numerically. In the experimental part, the effect of concrete compaction, casting method, and position are studied as parameters. Finite element analysis is performed to investigate failure mode, tensile and bond stress distributions, and the effect of the varying cross-section of the fiber strand. Compaction improved the splitting resistance for the vertically cast specimens. The compacted vertically cast specimens showed a higher splitting resistance than their horizontally cast equivalents. The finite element model indicated that the main cause of splitting failure is the textile reinforcement's varying cross-section coupled with its flat elliptical shape. The model also showed that the bond stress distribution depends on the fiber strand's geometric configuration. [ABSTRACT FROM AUTHOR]

The bond performance of fiber reinforced plastic (FRP) bars in seawater sea sand alkali activated concrete (SSASC) was investigated using pull-out test specimens. The effect of different concrete strengths, anchorage lengths, FRP bar types, and diameters on the bond performance were investiaged. Special emphasis was given to the applicability of the existing bond-slip constitutive models to FRP reinforced SSASC, which was investigated by calibrating well-known models to the experimental results. The correlation between the experimental curve and different bond-slip constitutive models is analyzed by calculating the R2 value. To verify the applicability of finite element analysis to SSASC and FRP bars system, numerical simulation was performed in ABAQUS finite element simulation software by setting the same conditions as the experimental variables. The results indicate that the Fan Xiaochun's model, which is the modifications of the MBPE model, has a high degree of correlation and is more suitable for SSASC and FRP bars system. The simulation results using ABAQUS finite element software are in good agreement with the experimental results. • We investigated the bond between FRP bars and alkali activated concrete (AAC). • We suggested bond-slip models for FRP-AAC. • AAC offers a potential solution for the effective use of FRP reinforcement. • The finite element model can be used for predicting bond behaviour of FRP-AAC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Recycling decontaminated CCA treated wood and general timber waste into a wood geopolymer cement (WGC) composites. • The WGC with the decontaminated wood chips showed higher mechanical properties than both the samples with CCA-treated and non-CCA-treated wood chips. • The compressive strength and MOE decreased as the wood content increased, while the MOR increased with the wood content peaking at WC/B ratio of 0.25. • The WGC with WC/B ratio of 0.1 to 0.25 meets the minimum requirement for making load bearing cinderblocks, while all the samples satisfy the minimum requirement for non-load bearing cinder blocks. • The compressive strength of the WGC generally showed a higher value when compared to similar purpose wood-Portland cement composites. Addressing critical societal challenges, such as climate change, resource depletion, and environmental protection, requires sustainable management of resources. This study reports on the results of an experimental program using waste wood, including chromium copper arsenic (CCA) treated wood, to produce ambiently cured geopolymer cement bonded wood composites (WGC), and the results are very encouraging. The composite exhibited a reasonable compressive strength, which ranged between 7 and 27 MPa inversely corresponding to the amount of wood per binder ratio ranging between 0.1 and 0.4, conferring it the possibility of being used as a building material. The compressive strength of the composite with 40% wood chips showed the lowest compressive strength with values of 9.79, 7.29, and 7.92 MPa for decontaminated, CCA-treated, and non-CCA-treated wood chips, respectively. The results indicated that for all the wood per binder ratios, the use of decontaminated wood chips significantly improves the compressive, flexural, and specific strength of the composites, as well as their ductility, compared to non-decontaminated CCA-treated and non-CCA-treated wood chips. This paves the way for using wood waste in sustainability oriented product development and manufacturing. [ABSTRACT FROM AUTHOR]