Specific features in operation of road construction equipment in the Far North

The development of the Far North goes hand in hand with the use of road construction equipment. The article addresses the main factors that affect the operation of this equipment in extremely cold climates. The effect of low temperatures on the operation of machines and individual units is examined. In particular, information is provided on the effect of low temperatures on operation of the hydraulic drive, power plants, and metal structures. The influence of the requirement to observe the methodological recommendations regarding the ergonomics and physiology of workers on increasing the cost of works with the use of road construction machinery has been noted.

7-Score Function for Assessing the Strength of Association Rules Applied for Construction Risk Quantifying

There are several factors influencing the time of construction project execution. The properties of the planned structure, the details of an order, and macroeconomic factors affect the project completion time. Every construction project is unique, but the data collected from previously completed projects help to plan the new one. The association analysis is a suitable tool for uncovering the rules—showing the influence of some factors appearing simultaneously. The input data to the association analysis must be preprocessed—every feature influencing the duration of the project must be divided into ranges. The number of features and the number of ranges (for each feature) create a very complicated combinatorial problem. The authors applied a metaheuristic tabu search algorithm to find the acceptable thresholds in the association analysis, increasing the strength of the rules found. The increase in the strength of the rules can help clients to avoid unfavorable sets of features, which in the past—with high confidence—significantly delayed projects. The new 7-score method can be used in various industries. This article shows its application to reduce the risk of a road construction contract delay. Importantly, the method is not based on expert opinions, but on historical data.

Practical Application of Nanotechnology Solutions in Pavement Engineering: Addressing Practical Road Construction Related Problems Using Marginal Materials Stabilised With New-Age (Nano) Modified Emulsions (Nme) Towards Sustainable Roads

The use of New-age (Nano) Modified Emulsions (NME) for the stabilisation of marginal materials for use in the upper-pavement layers of roads have been proven in laboratories, through Accelerated Pavement Tests (APT) and in practice. In addition, material design methods have been developed based on the scientific analysis of granular material mineralogy and the chemical interaction with the binder to design a material compatible NME stabilising agent for naturally available (often marginal) materials. However, the introduction of any new disruptive technology in a traditionally well-established industry, such as the road construction industry, is usually associated with considerable resistance. This is especially relevant when the new technology enables the use of granular materials traditionally considered to be of an unacceptable quality in combination with relatively new concepts such as New-age (Nano) Modified Emulsions (NME). In practice, few road construction projects are without any problems. The introduction of new-technologies obviously makes it an easy target to blame for any non-related problem that may arise during construction. This article aims to assist in pre-empting, recognising, preventing and resolving material or non-material related construction problems through the correct identification of the cause of the problem and recommending the best, most cost-effective way to correct any deficiencies on site.

Could road constructions be more hazardous than an earthquake in terms of mass movement?

Roads can have a significant impact on the frequency of mass wasting events in mountainous areas. However, characterizing the extent and pervasiveness of mass movements over time has rarely been documented due to limitations in available data sources to consistently map such events. We monitored the evolution of a road network and assessed its effect on mass movements for a 11-year window in Arhavi, Turkey. The main road construction projects run in the area are associated with a hydroelectric power plant as well as other road extension works and are clearly associated with the vast majority (90.1%) of mass movements in the area. We also notice that the overall number and size of the mass movements are much larger than in the naturally occurring comparison area. This means that the sediment load originating from the anthropogenically induced mass movements is larger than its counterpart associated with naturally occurring landslides. Notably, this extra sediment load could cause river channel aggregation, reduce accommodation space and as a consequence, it could lead to an increase in the probability and severity of flooding along the river channel. This marks a strong and negative effect of human activities on the natural course of earth surface processes. We also compare frequency-area distributions of human-induced mass movements mapped in this study and co-seismic landslide inventories from the literature. By doing so, we aim to better understand the consequences of human effects on mass movements in a comparative manner. Our findings show that the damage generated by the road construction in terms of sediment loads to river channels is compatible with the possible effect of a theoretical earthquake with a magnitude greater than Mw = 6.0.

Change in Properties of Bitumen Used for Road Construction in Bitumineral Mixtures

Premature destruction of asphalt concrete can be caused by the aging of bitumen, which is associated with a change in the physical and chemical properties of bitumen. The article shows that in most cases, the improvement of the characteristics of asphalt concrete is achieved through the introduction of additives that affect the basic properties of the bituminous binder, such as penetration, softening temperature, viscosity. The influence of the chemical composition of the mineral filler on the rate of bitumen aging has been experimentally proved. The obtained research data show that the increase in the rate of aging of bitumen is influenced by the compounds of silicon and aluminum. On the other hand, metals such as iron and titanium contribute to the preservation of the initial plasticity of bitumen, and the accumulation of asphaltenes in the structure of the bitumen-mineral mixture slows down.

Potential of Soil Stabilization Using Ground Granulated Blast Furnace Slag (GGBFS) and Fly Ash via Geopolymerization Method: A Review

Geopolymers, or also known as alkali-activated binders, have recently emerged as a viable alternative to conventional binders (cement) for soil stabilization. Geopolymers employ alkaline activation of industrial waste to create cementitious products inside treated soils, increasing the clayey soils’ mechanical and physical qualities. This paper aims to review the utilization of fly ash and ground granulated blast furnace slag (GGBFS)-based geopolymers for soil stabilization by enhancing strength. Previous research only used one type of precursor: fly ash or GGBFS, but the strength value obtained did not meet the ASTM D 4609 (<0.8 Mpa) standard required for soil-stabilizing criteria of road construction applications. This current research focused on the combination of two types of precursors, which are fly ash and GGBFS. The findings of an unconfined compressive strength (UCS) test on stabilized soil samples were discussed. Finally, the paper concludes that GGBFS and fly-ash-based geo-polymers for soil stabilization techniques can be successfully used as a binder for soil stabilization. However, additional research is required to meet the requirement of ASTM D 4609 standard in road construction applications, particularly in subgrade layers.

South Sudan: The SDF and “Protection of Civilians”

The Japan Engineering Groups (JEG) deployment to the United Nations Mission in South Sudan (UNMISS) from 2012 to 2017 exhibited consecutive aspects of “integration” and “robustness.” During the first two years, Japan’s method of “integration,” or the “All Japan” approach, fit well with UNMISS’s focus on statebuilding. It yielded various outcomes, not only in the restoration of facilities and infrastructure (e.g., road construction) but also in the nonengineering support provided to the locals (e.g., job training). With the outbreak of de facto civil war in December 2013, however, UNMISS’s top priority moved from statebuilding to Protection of Civilians (PoC), thereby intensifying inclinations toward “robustness.” Afterward, the JEG mostly focused on the construction of a PoC site, that is, a shelter for evacuated locals and internally displaced people. While security in South Sudan continued to deteriorate, the amendment to the Peacekeeping Operations (PKO) Act as part of the 2015 Peace and Security Legislation enabled the Government of Japan (GoJ) to assign the JEG to partial security missions, such as the “coming-to-aid” duty. In the end, however, the GoJ abruptly withdrew the JEG in May 2017, thereby discontinuing the series of SDF deployments to United Nations Peacekeeping Operations since 1992.

Sustainable deployment of crushed concrete aggregates strengthened with cement and sand

Purpose: Paper assessed the feasibility of crushed concrete aggregates (CCA), a subsidiary of construction and demolition (C&D) waste, blended with cement and sand to form a composite for civil engineering field applications. Design/methodology/approach: The compaction and strength characteristics of CCA were observed by conducting Proctor compaction and California Bearing Ratio (CBR) tests. Different proportions of CCA, sand and cement were used. Moreover, the effect of curing period (0, 4, 7, 14 and 28 days) was also studied. In addition, regression analyses were performed to develop empirical expressions to predict the compaction and strength characteristics of the CCA composite. Findings: Increasing the CCA content up to 50% increases the maximum dry unit weight (MDUW) and decreases the optimum moisture content (OMC). However, on further increasing its content the MDUW decreases and OMC increases. Percent increase in the CBR value can go up to 412% if the CCA content is increased up to 50%. However, the percent reduction in CBR of about 20% can take place if 100% CCA content is used. Moreover, multiple regression shows that the experimental results are in good agreement with the predicted values. Research limitations/implications: The results obtained are purely dependent on the type of material. However, they are in favour of the used material as a probable option for road sub-base layer, and also for reducing burden on available natural resources. Therefore, it is recommended to conduct some initial tests to confirm the feasibility of the material. Practical implications: The proposed study will guide the design Engineers to choose CCA as one of the potential materials for road construction. Originality/value: It was observed that there is a need to maximize the utilization of C&D waste without making any compromise with its mechanical properties. So keeping that in view, the present study was conducted.