Sustainable foam lightweight soil (FLS) with the introduction of solid waste-based binders and dredged mud has shown high engineering and environmental value in expressway reconstruction and extension projects. Accelerated testing through high-temperature curing is considered a crucial method for early-stage assessment of sustainable FLS construction quality. This study aims to explore the curing temperature effect on the strength development of the FLS with different mix proportions and the applicability of accelerated curing method. Strength tests were first conducted on kaolin clay-based FLS with three wet densities and three water contents under different curing temperatures (T), and the strength of the dredged mud-based FLS was also tested to broaden the applicability. Results indicate that higher T and increased wet density significantly enhance the strength of clay-based FLS at any curing age, while higher water content reduces it. The wet density and water content of the proposed FLS recommended in this study considering the strength and lightweight requirements are 800 kg/m3 and 100%, respectively. Moreover, the effectiveness of the accelerated aging method for clay-based FLS is demonstrated by the fact that no dramatic strength loss occurs due to foam expansion and collapse at elevated T of up to 50 degrees C. On this basis, a strength prediction model based on the concept of activation energy is proposed for both kaolin clay-based and dredged mud-based FLS considering the temperature effect. Changes in wet density have a minimal impact on model parameters, but variations in soil type and water content require updating these parameters to ensure prediction accuracy. Finally, an early quality control method is introduced for applying the sustainable FLS in field projects.

The escalating global issue of soil pollution by heavy metals, particularly incinerated municipal solid waste fly ash (IMSWFA), necessitates effective remediation strategies. The prevailing approach for safely disposing and utilization of IMSWFA involves high-temperature sintering. In this work, we propose a cost-effective method to produce ceramsites by utilizing IMSWFA, municipal sludge (MS), contaminated soil (CS), and iron tail slag (ITS). After conducting a comprehensive analysis and comparison of outcomes obtained from orthogonal experiments and single-factor experiments, it was determined that the optimal preparation conditions for achieving desirable results are preheating at a temperature of 400 degrees C for 15 min followed by sintering at a temperature of 1150 degrees C for 10 min. The optimal ratio of raw materials for ceramsites is 15 % IMSWFA, 15 % MS, 58 % CS, and 12 % ITS. The ceramsites, prepared in accordance with the specified process and raw material ratio, exhibit remarkable properties including robust stability, minimal water absorption, reduced weight, and elevated cylindrical compressive strength. The ceramsites demonstrate an exceptionally high heavy metal loss ratio ranging from 91 % to 100 %, while exhibiting significantly lower leaching quantities of these metals compared to the raw materials. Additionally, aging tests of ceramsites were performed under UV light and acid/alkaline etching to simulate the real-world environment. This work can be utilized to investigate the long-term environmental impact of ceramsites derived from municipal solid waste (MSW), thereby making a valuable contribution to the advancement of solid waste management technology.

Biodegradable polyesters are excellent candidates for sustainable packaging and mulch films. Poly(butylene succinate terephthalate) (PBST) and poly(glycolic acid) (PGA) possess excellent barrier properties and specific mechanical properties. Herein, reactive melt-blending of PGA and poly(butylene adipate-co-terephthalate) (PBAT) using a multifunctional epoxy oligomer (ADR) and diphenylmethane diisocyanate (MDI) was conducted to improve their mechanical performance and processability. With increasing content of the compatibilizer, the cross-sectional microstructure showed a decreased phase size and blurred interface, which effectively improved the interfacial adhesion and compatibility. Compared to PBST/PGA blend films without compatibilizers, the tensile strength increased from 32.8 to 39.4 or 47.2 MPa after addition of 0.1 ADR or 0.5 MDI. The tear strength increased from 146.2 to 162.1 or 174.1 N/mm. Meanwhile, the compatibilized PBST/PGA films showed stable barrier properties and maintained their mechanical properties when subjected to an ultraviolet light accelerated aging test. Finally, a field trial was carried out using the blown PBST/PGA mulch films spanning nearly four months to assess their processability for practical application. Thus, this work promotes a sustainable PBST/PGA film with excellent strength and barrier properties, made via a reactive melt-blending method, that shows great potential as an agricultural mulch film.

In this paper, several hundred specimens were compacted and tested to evaluate the potential of beam testing protocols to directly measure four mechanical properties from one beam. Mechanical properties measured through beam testing protocols were compared to properties of plastic mold (PM) device specimens and were found to be comparable once specimen densities were corrected. Mechanical properties were also used to quantify mechanical property relationships, often used as pavement design inputs. When compared to traditionally recommended mechanical property relationships, relationships between elastic modulus and unconfined compressive strength, as well as modulus of rupture and unconfined compressive strength, were overly conservative; however, indirect tensile strength and unconfined compressive strength relationships from the literature were accurate. This paper also assessed an elevated-temperature curing protocol to simulate later-life pavement mechanical properties on laboratory specimens. Mechanical properties of laboratory specimens that underwent accelerated curing were shown to be comparable to 10- to 54-year-old cores taken from Mississippi highways.