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To delay the expansion of reflective cracks on semi-rigid base asphalt pavements and strengthen the cracking resistance of asphalt rubber stress-absorbing membrane interlayers, the bonding and fracture performances as well as cracking resistance of a fiber-reinforced asphalt rubber stress-absorbing membrane interlayer (FAR-SAMI), rubber asphalt stress-absorbing membrane interlayer (AR-SAMI), and SBS-modified asphalt stress-absorbing membrane interlayer (AS-SAMI) were studied. In addition, the resistance to reflective cracking for FAR-SAMI was evaluated by finite element (FE) analysis. The results show that FAR-SAMI exhibits appropriate bonding performance at 15 and 40 ° C. The addition of glass fiber increases the toughness of the composite specimens and the fracture energy of FAR-SAMI increases by 23% compared with AR-SAMI. Furthermore, FAR-SAMI is effective in restraining the development of reflection cracks and prolonging the fatigue life. FE analysis also shows that FAR-SAMI can significantly reduce the stress concentration phenomenon in the crack. Therefore, fiber-reinforced asphalt rubber was found to be suitable as a SAMI to prevent and control reflective cracking. [ABSTRACT FROM AUTHOR]

A glass fiber-reinforced epoxy (GFRE) composite, constituted by glass fibers in off-axis directions, i.e., [± 45°]2S was considered in this investigation for evaluating its static and fatigue behaviors. During the tensile test, GFRE composites exhibited nonlinear behavior, and subsequently reaching the ultimate point, test specimens rapidly failed owing to fiber failure. Fatigue tests were conducted under completely reversed rotating bending loads. The fatigue degradation model suggested by Hwang and Han was adopted to illustrate the effect of five different stress levels and test frequency (10 Hz) on the fatigue life of GFRE composites. From the obtained results, it was evident that the fatigue degradation model suggested by Hwang and Han shows good agreement with experimental results as compared to the S–N curve and Basquin's approaches. From SEM results, matrix cracking and fiber pullout were observed at lower stress levels, whereas under higher stress levels propagation of cracks in the longitudinal direction was majorly responsible for catastrophic failure of fibers. [ABSTRACT FROM AUTHOR]

Highlights • We reviewed the asphalt mixes modified with lignin fiber and glass fiber. • Studied of rutting, water damage, thermal and fatigue cracking in asphalt mixes. • Lignin fiber improves the resistance to low temperature cracking in asphalt mixes. • Glass fiber improves the high temperature performance in asphalt mixes. • Both fibers improve fatigue performance and water stability in asphalt mixes. Abstract Low temperature thermal cracking, rutting, moisture damage and fatigue cracking are popular damages that appear in the asphalt mixture. These problems occur mainly because of the growth in the number of heavy load vehicles, design and construction errors and environmental condition that reduce the quality, performance and the service life of the pavement. Several previous studies showed that using additives like fibers to modify asphalt mixtures could enhance the efficiency and boost the quality and service life of the pavement. This paper presents a review of the role of lignin and glass fiber as a modifier in bituminous mixes. To evaluate some main mixture properties, some tests such as the low temperature bending, indirect tensile strength, the wheel loading tracking, Hamburg wheel tracking, Marshall immersion, freezing-thaw splitting, third-point bending fatigue and indirect tensile fatigue are applied to analyze rutting, low temperature cracking resistance, moisture damage resistance and fatigue resistance of asphalt mixture modified with lignin or glass fiber. Results denoted that the quality of asphalt mixture enhanced significantly by adding lignin fiber or glass fiber. Previous researches demonstrated an obvious improvement in low temperature performance in the pavement when adding 0.2–0.4% lignin fiber of asphalt mixtures, with a limited improvement of high temperature performance. On the contrary, the asphalt mixtures modified with 0.2–0.6% glass fiber of asphalt mixtures significantly improved the resistance of high temperature. So it is hard to improve all the performances of the mixture by using only a single admixture at the same time. Thus, a new way of modifying asphalt mixture that is called double-mixture technology or composite modification, which is able to enhance the overall properties of asphalt mixture. [ABSTRACT FROM AUTHOR]

The synergetic effect of multi-walled carbon nanotubes (MWCNTs), carbon fiber (CF), and glass fiber (GF) on the static and dynamic mechanical and thermal properties of MWCNTs/epoxy (EP), carbon fiber reinforced polymer (CFRP), and glass fiber reinforced polymer (GFRP)/EP composites were studied. Impact, tensile, and flexural strengths and fatigue cycles of MWCNTs/EP, MWCNTs/CFRP/EP, MWCNTs/GFRP/EP were increased with an increase of MWCNTs content in the epoxy resins. The impact strength of MWCNTs/EP composite is increased dramatically from 4.8 J/M (neat resin) to 12.2 J/M (increased 154.1%) by adding 2.0 phr MWCNTs in the composites. The tensile strength of MWCNTs/CFRP/EP was enhanced from 580.1 MPa (CFRP/EP) to 781.4 MPa (increased 34.7%) by adding 0.5 phr MWCNTs. In addition, the flexural strength of MWCNTs/GFRP/EP was increased from 244.1 MPa (GFRP/EP) to 298.1 MPa (increased 22.16%) by adding 0.75 phr MWCNTs. The fatigue cycles of MWCNTs/GFRP/EP were increased from 959 cycles (GFRP/EP) to 3232 cycles (increased 237%) by adding 2.0 phr MWCNTs. The coefficient of thermal expansion (CTE) of MWCNTs/CFRP/EP was decreased significantly by adding 2.0 phr MWCNTs. The CTE of GFRP/EP had a value of 65.5 ppm/°C by adding 2.0 phr MWCNTs and was lower than that of CFRP/EP. [ABSTRACT FROM AUTHOR]