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This study presents a utilization of asphalt waste dust (AD) as a filler material to replace sand in a mortar. Moreover, fly ash (FA) is utilized as an additive of pozzolanic material. The compressive strength and microstructures were investigated to propose the suitable ratio of AD and FA for sustainable mortar. All samples were fixed with a mixing ratio of ordinary Portland cement (CM): sand (Si) at 1: 2.75. The Si was replaced by AD content at 0, 50, 60, 70, 80, 90, and 100% by weight (%wt) of Si, respectively. Furthermore, the FA was added to the suitable mixing conditions of CM, AD, and Si, which is called the suitable mortar containing AD, at 0, 10, 20, 30, and 40 %wt. The results from the compressive strength test were evaluated and compared under the different curing times for 3, 7, and 28 days in saturated limewater. The microstructures of testing samples were analyzed using different characterization techniques including X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (SEM-EDS). From the results, the mortar containing AD showed higher compressive strength than those without AD. After the addition of FA and AD, the compressive strength was more increased rather than using AD without FA. Sand can be replaced with AD as filler aggregates to reduce voids in the mortar. Additionally, FA can be used as a pozzolanic additive in mortars. Therefore, those two waste materials (AD and FA) are alternative materials suitable for use in the development of compressive strength in mortar.

Seismic response analysis is a key aspect in earthquake geotechnical engineering, as it provides important insights into the behavior of soils when exposed to seismic forces. This research compares equivalent linear and non-linear models in the central coastal region of Bengkulu, which is known for its complex geology and high seismicity. By evaluating the accuracy and reliability of each model in predicting ground motion amplification, this research aims to provide useful recommendations for seismic design. The research method uses one-dimensional equivalent linear and nonlinear propagation modeling, namely Pressure Dependent Hyperbolic (PDH). The analysis resulted in the parameters of Peak Ground Acceleration (PGA), time history acceleration, spectral response acceleration, and amplification factor. The equivalent linear method consistently produced higher values for peak ground acceleration (PGA), spectral response acceleration, time history acceleration, and amplification factor compared to the nonlinear method. The analysis results show that the equivalent linear PGA values are in the range of 0.32g to 0.63g, while the nonlinear values range from 0.20g to 0.52g. The resulting spectral responses are averaged over the design spectrum within 0.2s to 0.9s, which can affect low-to high-ceilinged buildings. The equivalent linear amplification factor has a range of 1.59 to 1.91, while the nonlinear has a range of 0.80 to 1.59. Both methods have their advantages, with the nonlinear approach offering greater accuracy for large seismic events, while the equivalent linear model remains useful for preliminary analysis. Hopefully, these findings will improve the understanding of ground response in coastal areas and provide valuable data for improving infrastructure resilience in earthquake-prone areas around the world. [ABSTRACT FROM AUTHOR]

The utilization of a mechanically stabilized earth wall (MSE wall) is prevalent due to its stability and cost-effectiveness compared to conventional earthwork construction methods. In addition, the railway transportation infrastructure has played a vital role in connecting Thailand's numerous regions. The behavior of a 6-m-high MSE wall constructed on a hard ground foundation, which was reinforced with high-density polyethylene on one side and a metallic strip on the other side, was studied in this research. The purpose of this MSE wall is to support the railway structure under dynamic train loads at 100, 150, and 200 km/h. The three-dimensional finite-element method was used to simulate and investigate the behavior of the MSE wall in terms of lateral displacement, settlement, and strain of reinforcement materials. The findings of the study demonstrate that there is a positive correlation between train speed and both lateral displacement and settlement. This relationship is most pronounced at the top of the MSE wall, which is primarily attributable to the influence of surface waves. The MSE wall's behavior under the influence of dynamic train loads was most prominently displayed by the surface waves, which were a curved wavefront at 150 km/h and a Mach cone at 200 km/h. The settlement profile increased when the speed of dynamic train loads increased. The impact of velocity fluctuations on the strain of the reinforcement material was insignificant. Due to the hard ground foundation, the behavior of the MSE wall on both types of reinforcement materials exhibited similar tendencies. Moreover, it was observed that the maximum tension lines closely follow the bilinear coherent gravity method with a standard distance of 0.3H from the facing, where H represents the equivalent height of the MSE wall. [ABSTRACT FROM AUTHOR]

The pile-retaining wall at Nonthaburi rural road no. 5036 was constructed using reinforced concrete piles or driven piles combined with a concrete retaining wall. The purpose of this structure was to enhance the slope stability of the canal-side road (road embankment along the canal). The damage to the driven piles occurred during the pile construction at 18 m depth below the ground surface. The resistivity survey and screw driving sounding test were employed to investigate the thickness of soft clay layers and unexpected stiff soil layers at the failure area. The field vane shear test was employed to investigate the sensitivity of the soft clay layer. Furthermore, the finite element model was analyzed to verify the failure behaviour of the road embankment during the driven pile's construction. Consequently, the investigation revealed that the subsoil in the failure area exhibited sensitivity values. The subsoil consisted of a layer of soft clay to medium stiff clay, ranging from 2-10 m below the ground surface, while the subsoil consisted of stiff clay below a depth of 10 m. The installation of the 18-m driven pile caused a disturbance in the soft sensitive clay layer above the stiff soil layer, resulting in a reduction in the strength of the soft clay and affecting the displacement of the driven pile during construction. Furthermore, the occurrence of rapid drawdown causes water seepage to continue to flow toward the canal side. This phenomenon produces active forces on the slope of the road embankment along the canal. As a result, the road embankment along the canal side can collapse due to a disturbance in the sensitive clay layer with rapid drawdown. The result was agreed with the study findings obtained by the finite element model. [ABSTRACT FROM AUTHOR]