Concerns about the environment, the cost of energy, and safety mean that low-energy cold-mix asphalt materials are very interesting as a potential replacement for present-day hot mix asphalt. The main disadvantage of cold bituminous emulsion mixtures is their poor early life strength, meaning they require a long time to achieve mature strength. This research work aims to study the protentional utilization of waste and by-product materials as a filler in cold emulsion mixtures with mechanical properties comparable to those of traditional hot mix asphalt. Accordingly, cold mix asphalt was prepared to utilize paper sludge ash (PSA) and cement kiln dust (CKD) as a substitution for conventional mineral filler with percentages ranging from 0–6% and 0–4%, respectively. Test results have shown that the incorporation of such waste materials reflected a significant improvement in the mixture’s stiffness and strength evolution. The cementitious reactivity of PSA produces bonding inside the mixtures, while CKD is used as an additive to activate the hydration process of PSA. Therefore, based on the results, it will be easier to build cold mixtures by shortening the amount of time needed to reach full curing conditions.

The aim of this research was to develop a sustainable and ecologically sound, non-traditional cold mix asphalt (CMA) that can be used in the construction industry. This new type of CMA incorporates wastewater sludge fly ash (UFA) and bottom ash (UBA) as a replacement filler for ordinary Portland cement and limestone. Silica fume (SF) was also used as an additional filler. The mechanical and durability characteristics of the new CMAs were examined in terms of indirect tensile stiffness modulus (ITSM), and rutting, fatigue, water and fuel resistance. The results showed that CMA with 2.1% OPC +3.9% UFA at 3 days of age, had ITSM values 11 times that of traditional CMA, while CMA with 2.1% OPC+ 3.3% UFA +0.6% UBA, had ITSM values 5 times that of traditional CMA at 28 days of age. SF activated hydration for both mixes, significantly increasing ITSM. These results indicate that CMA has a comparable mechanical performance to standard Hot Mix Asphalt (HMA) mixtures for use as surface pavement layers. This study offers a novel CMA with improved mechanical performance. It is economically effective and ecologically beneficial, compared to HMA, due to its ability to accommodate wastewater sludge ashes that are often disposed of in landfill sites.

This paper aims to explore the current state of the art and potential of 3D concrete printing and its use in large-scale applications. The study analysed 373 academic research, all of which were obtained from the Scopus database. The review conducted on some crucial issues on development of 3D concrete that included materials and their desirable properties, printer nozzle developments, reinforcement in printing, geopolymers as printing materials, and the use of coarse graded aggregates. This study provides researchers and institutions with an in-depth insight into 3D concrete printing and research trends worldwide and assesses the future of 3D concrete printing in large-scale applications. The requirement of more research on the mechanics of 3D printers, standardising a printer nozzle, the automation of reinforcing processes, and use of coarse graded aggregate for large-scale structural application were identified in this review. It also shows how 3D concrete printing has evolved and changed over time and gives an insight into the future of 3D concrete printing—making this scientometric review a framework for future studies.

Evapotranspiration represents one of the main parameters in the hydrological cycle. It is usually expressed by the term Reference evapotranspiration (ETo), that is affected by some meteorological parameters. This study aims to find the difference amount in reference evapotranspiration (ETo)...

The use of Bubble Deck in modern prefabricated construction methods has recently become widespread in industrial projects worldwide. In the middle of a typical slab, Bubble Deck places hollow plastic balls that do not improve structural performance but significantly reduce structural weight. This study analyzes the behavior of self-uniting bidirectional concrete slabs with plastic spherical voids under high temperatures and for different periods. Six simply supported bidirectional plates, five of which contained bubbles and one solid, were numerically tested using the finite element method and the commercial ABAQUS software to investigate the behavior of bidirectional plates fired at various temperatures and for various amounts of time. Each slab has the following measurements: (1500*1500*150) mm. These slabs were fired at different temperatures (600 and 800) °C and for different periods (one and two hours). The slabs were classified into four groups depending on the kind of slab (solid or bubble), the degree of burning (600 and 800) °C, and the duration of the burning (one and two hours). The loading strength of concrete was found to be up to 65% less than the maximum capacity of a slab that was bubbled and fired at high temperatures. The length of the firing time also had a significant effect on reducing the strength of the concrete. The longer the firing period, the lower the load resistance of the concrete. The ball would melt and scorch in an intense, protracted fire without noticeable effects. The ability of the steel to maintain adequate strength during a fire, when it will be burned and lose significant strength as the temperature rises, determines the slab’s ability to withstand fire. Bubble deck slabs produce between 17% and 39% stronger thermal resistance than an equivalent solid slab of the same depth, even though they are not intended to provide thermal insulation due to the encapsulation of the air bubbles within the center of the concrete slab.

The main concept of using waste and recycled materials as modifiers for construction materials, is to improve their performance, keep the resources, and conserve the environment from pollution problems. This investigation is tended to evaluate the effect of using two different types of modifiers on the physical properties of asphalt binder. The modifiers are Recycled-Low-Density-Polyethylene (R-LDPE) polymer and waste-Paper Fiber (w-PF), they were mixed individually and collectively with neat asphalt binder. The first set of modified binders comprised neat binder with 3% R-LDPE alone, the second is comprised 0.3%, 0.5% and 0.7% of w-PF alone, while the third comprised collective modifiers of 3% R-LDPE and 0.3%, 0.5% and 0.7% w-PF. The influence of these modifiers on neat asphalt binder was evaluated in terms of penetration (Pen.), softening point (SP), penetration index (PI), ductility, rotational viscosity (RV), penetration aging index (PAI) and softening point index (SPI). The obtained results indicate that the utilization of modifiers helps in improving the physical properties of asphalt binders by different levels. the modification by collective modifiers leads to an increase SP, RV, PI, PAI, and SPI to 65%, 2 times, 1.044, 0.93, 2.5 respectively compared to neat bitumen. As well, leads to a decrease in both Pen. and ductility to the levels 45% and 79% respectively. This indicates that the use of waste and recycled modifiers especially in the combined form encourage the production of comparative modified asphalt binder.