Mineral admixtures and waste by-products in concrete exhibit economical and environmental benefits, but their cementing and engineering properties should be assessed before practical adoption. In this study, we investigated hydration and physical properties of Self-Consolidating (SCM) and Ordinary (OM) mortars, based on slag-blended Portland limestone cement (PLC), with equivalent water-to-cement ratio (E/C≈ 0.55). The variables were mortar type and mineral admixture type, limestone powder (LP) or silica fume (SF). Therefore, we made two ordinary mortars (OMs), Oref (OPC based) and Oplc (slag PLC based), and two self-consolidating mortars (SCMs), SplcL (limestone based) and SplcS (silica fume based). We assessed compressive strength, sorptivity, hydration heat, thermogravimetric analysis, and SEM images. Results reveal that Oplc exhibits similar to better performance than Oref; blended LP leads to 36% higher mechanical strength, more than 50% carboaluminate in SCMs, and 40% lower heat and rate of hydration, and seems to have packing role and doesn't contribute to more sites’ nucleation; SF is efficient when substituted more than 10%.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The adoption of natural fiber reinforced polymer (FRP) composites as an eco-friendly substitute for synthetic FRPs in structural strengthening applications is gaining substantial momentum. This study delves into the effectiveness of jute fabric reinforced epoxy composites in bolstering the flexural strength of impaired concrete beams. An array of variables, encompassing the number of fabric layers (ranging from 1 to 3), fiber heat treatment, externally bonded reinforcement (EBR) configuration (soffit vs. U-shape), and fiber type (jute vs. glass), underwent systematic scrutiny. The comprehensive analysis of 30 pre-cracked high-performance concrete beams yielded compelling findings. In particular, the application of heat-treated jute EBR, especially when employing two or three layers, resulted in significant increases in peak loads, translating to improvements ranging from 85 to 120% when compared to the control beam. This treatment significantly improves the bond between the fibers and the matrix, consequently enhancing the structural performance. Notably, jute composites can attain equivalent strengthening performance compared to glass FRP while offering substantial cost savings and significantly reducing carbon emissions, rendering them a more environmentally sustainable and economically viable choice.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.