Sustainable Transportation Infrastructures in Iowa—Goals and Practices

The need to incorporate sustainability principles and practices is increasing for environmental and economic reasons. It is imperative to identify and operationalize sustainability strategies into core administrative, planning, design, construction, operational, and maintenance activities for the transportation infrastructure systems by integrating sustainability into decision-making processes. The primary goal of this study is to develop an implementation plan for achieving more sustainable transportation infrastructure systems in Iowa. This research aims to guide the adoption of sustainable strategies, balancing cost, performance, and environmental impact in transportation infrastructure development. This paper presents efforts to develop a methodology for identifying the best sustainable practices for implementation in transportation infrastructure practices in Iowa by surveying state DOTs to learn about their sustainability goals and practices, identifying existing sustainability attributes and sustainable practices, and developing a GIS database where construction, materials and performance data of sustainable practices can be stored and analyzed

Consistent Foamed Asphalt Contents Needed for Cold In-Place Recycled Pavement Layers in Practice

Cores were recovered from the right wheel path and between wheel paths at 8 locations US 34 in Mills and Wapello Counties. The cores were cut into discs to isolate the pavement layers and the discs were fabricated into semicircular bending test specimens. Asphalt contents among CIR cores varied significantly and that CIR specimens with higher asphalt binder contents exhibited higher flexibility index values. From the output of these tests, the CIR pavement layers were found to be more flexible in comparison to the HMA layers, that CIR layers have higher flexibility that allow them to serve as a stress relieving layer and mitigate reflective cracking

Development of Smart Pavement Design Sensitivity Analysis Software for Asset Management System

There are a number of pavement management systems, but most of them are limited in providing pavement design and pavement design sensitivity information. This paper presents efforts towards the integrated pavement design and management system, by developing smart pavement design sensitivity analysis software. In this paper, the sensitivity analyses of critical design input parameters have been performed to identify input parameters which have the most significant impacts on the pavement thickness. Based on the existing pavement design procedures and their sensitivity analysis results, a smart pavement design sensitivity analysis (PDSA) software package was developed, to allow a user to retrieve the most appropriate pavement thickness and immediately perform pavement design sensitivity analysis. The PDSA software is a useful tool for managing pavements, by allowing a user to instantaneously retrieve a pavement design for a given condition from the database and perform a design sensitivity analysis without running actual pavement design programs. The proposed smart PDSA software would result in the most efficient pavement management system, by incorporating the optimum pavement thickness as part of the pavement management process

Locomotive mechanism design and fabrication of biomimetic micro robot using shape memory alloy

Abstract-Recently, micro robots have been applied in various industrial areas. Some of them are requested to be able to move in small space or rough environment that people can not reach. It is necessary to have a capability to move at even overturned and adapt simple mechanism to fabricate it easily with small size. In this paper, a novel bio-mimetic micro robot with simple mechanism using shape memory alloy (SMA) is introduced to generate earthworm-like locomotive motion. There have been many kinds of mobile micro robot using the SMA. However, these actuators generally require electric cable for power supply, which might have an adverse effect on the mobility of the micro robot. The proposed micro robot system is composed of an actuator with SMA spring and silicone bellows, wireless control system, wireless power supply (battery) and body frames. The robot is also analyzed to customize required specifications. After the design and experiment, we find out that the micro robot can move a wireless free motion and be fabricated easily. Like an earthworm, the robot can travel on uneven, slippery and flexible environment

Development of Warm In-Place Recycling Technique as an Eco-Friendly Asphalt Rehabilitation Method

Cold In-place Recycling (CIR) has been widely used in the world since it is easy to apply it in the field at a low cost. However, it is not normally used as a surface layer as a result of its inconsistent quality due to an excessive amount of fine aggregates pulverized during the milling process. Hot In-place Recycling (HIR) can retain the original shape of the aggregates, but it often produces a large amount of Volatile Organic Compounds (VOCs). Therefore, a third in-place recycling technique is introduced in this paper: Warm In-place Recycling (WIR). The WIR technique overcomes the limitations of both CIR and HIR techniques by lowering a heating temperature while adding a Tetraethylenepentamine (TEPA)/Soybean/SBS additive. To identify the effect of the additive on the RTFO-aged binder, viscosity and dynamic modulus values were measured at different temperatures. Based on Hamburg Wheel Tracking (HWT) and Disc-Shaped Compact Tension (DCT) tests, the additive improved the moisture susceptibility and low temperature cracking resistance. The indirect infrared heating equipment reduced the emission by lowering the pavement surface heating temperature by 20 °C from 140 to 120 °C. Compared with the heating at 140 °C, the LPG usage for heating at 140 °C was lowered by 21%. The proposed WIR equipment with an additive would revolutionize the in-place recycling practices

Changes in the Earth’s Spin Rotation due to the Atmospheric Effects and Reduction in Glaciers

The atmosphere strongly affects the Earth’s spin rotation in wide range of timescale from daily to annual. Its dominant role in the seasonal perturbations of both the pole position and spinning rate of the Earth is once again confirmed by a comparison of two recent data sets; i) the Earth orientation parameter and ii) the global atmospheric state. The atmospheric semi-diurnal tide has been known to be a source of the Earth’s spin acceleration, and its magnitude is re-estimated by using an enhanced formulation and an up-dated empirical atmospheric S2 tide model. During the last twenty years, an unusual eastward drift of the Earth’s pole has been observed. The change in the Earth’s inertia tensor due to glacier mass redistribution is directly assessed, and the recent eastward movement of the pole is ascribed to this change. Furthermore, the associated changes in the length of day and UT1 are estimated

Changes in the Earth's Spin Rotation due to the Atmospheric Effects and Reduction in Glaciers

The atmosphere strongly affects the Earth’s spin rotation in wide range of timescale from daily to annual. Its dominant role in the seasonal perturbations of both the pole position and spinning rate of the Earth is once again confirmed by a comparison of two recent data sets; i) the Earth orientation parameter and ii) the global atmospheric state. The atmospheric semi-diurnal tide has been known to be a source of the Earth’s spin acceleration, and its magnitude is re-estimated by using an enhanced formulation and an up-dated empirical atmospheric S2 tide model. During the last twenty years, an unusual eastward drift of the Earth’s pole has been observed. The change in the Earth’s inertia tensor due to glacier mass redistribution is directly assessed, and the recent eastward movement of the pole is ascribed to this change. Furthermore, the associated changes in the length of day and UT1 are estimated