Evaluation of Field and Laboratory Stiffness of Recycled Materials Used in Pavement Base Layers

2020 ◽  
Author(s):  
Haluk Sinan Coban ◽  
Bora Cetin ◽  
Halil Ceylan ◽  
Tuncer B. Edil ◽  
Soheil Nazarian
Author(s):  
Caroline O'Donnell ◽  
Dillon Pranger

This chapter will study the proliferation of architectural follies that use recycled or recyclable materials in a move to promote better practices in waste and recycling. Given the slow uptake of this impetus in the architectural world proper, the text will investigate the obstacles in engaging in materially sustainable practices in the construction industry as well as case studies for rethinking currently problematic materials. However, while some improvements have been made in the construction industry's use of recycled materials, the industry often dismisses the afterlife of materials used throughout the process. What are the motivations of the industry and how can we incentivize circular thinking in an industry that produces hundreds of millions of tons of waste per year in the US?


Author(s):  
Rui Xiao ◽  
Pawel Polaczyk ◽  
Miaomiao Zhang ◽  
Xi Jiang ◽  
Yiyuan Zhang ◽  
...  

As the concept of sustainable pavement gains prominence, a growing number of industrial wastes and recycled materials have been utilized in the pavement industry to preserve natural resources. This study investigates the potential use of waste glass powder-based geopolymer cement as a stabilizing agent in recycled waste glass aggregate (GA) bases. Two recycled materials, waste glass powder (GP) and class F fly ash (FF), were used as the raw materials in the preparation of geopolymer. Virgin aggregate (VA) was replaced by GA at varying replacement ratios as the pavement base materials, and the mechanical behaviors before and after geopolymer stabilization were evaluated. Without stabilization, the incorporation of over 10% GA caused significant detrimental effects on the California bearing ratios (CBR) of base materials, which should be carefully managed in pavement construction. However, all geopolymer stabilized samples showed decent strength properties, indicating the effectiveness of geopolymer stabilization. The use of GA reduced the drying shrinkage of base samples, although the mechanical properties were compromised. During the sample preparation, a higher curing temperature and relative humidity resulted in better mechanical behaviors, and the surface of GA could dissolve in alkaline solution and involve in the geopolymerization at 40°C. The microstructure and minerology of geopolymer stabilizer of base materials were characterized by scanning electron microscopy (SEM) and X-ray defraction (XRD) analyses. This study confirmed the promise of using waste glass-based pavement base materials as the greener substitutes and the potential synergy between waste glass recycling and the pavement industry.


2019 ◽  
Vol 667 ◽  
pp. 359-370 ◽  
Author(s):  
A.R. Fernandes ◽  
I.R. Lake ◽  
A. Dowding ◽  
M. Rose ◽  
N.R. Jones ◽  
...  

Author(s):  
Yuanjie Xiao ◽  
Erol Tutumluer ◽  
Debakanta Mishra

Permanent deformation or rutting is the main performance indicator of unbound aggregate layers used in flexible pavements. This paper evaluates the prediction abilities of unbound aggregate base or subbase permanent deformation models in use or proposed for use in the Mechanistic–Empirical Pavement Design Guide (MEPDG) approach. Repeated load triaxial-type permanent deformation tests were conducted on three unbound aggregate materials—limestone, dolomite, and uncrushed gravel—commonly used for pavement base and subbase and subgrade replacement applications in Illinois. The test matrix was designed to evaluate effects of aggregate physical properties, including moisture content, gradation, types and amounts of fines, aggregate mineralogy, and particle shape, texture, and angularity. The laboratory-measured permanent deformations were compared with those predicted by four rutting models evaluated in this study. The permanent deformations predicted by the original 1989 Tseng–Lytton model and the 2006 El-Badawy model were generally in good agreement with the measured values. The current MEPDG rutting model and its enhanced version proposed in 2013 by Hashem and Zapata tended to overpredict permanent deformations and have a low sensitivity to changes in aggregate physical properties. In addition to enhancements recommended for the four evaluated models, a unified rutting model was developed; it used a shear stress ratio concept and imaging-based aggregate morphological indexes. With a single set of calibrated model parameters, the unified rutting model produced reasonably accurate permanent strain predictions for all unbound aggregate materials used in this study.


2013 ◽  
Vol 364 ◽  
pp. 716-720 ◽  
Author(s):  
An Xie ◽  
Huan Lin Jin ◽  
Ming Zhang

As a kind of general-purpose plastic, PP possesses a good mechanical property and excellent resistance to chemical attack. So, now, it is widely used. In this article, a kind of decorating materials used in automobile and rubber powders were used to undertake a modification of PP. Besides, mechanical property was tested and SEM,TMA,TG technology were used to investigate some of the property of composites. We drew a conclusion that the composite with a ternary system consists of PP,POE and rubber powder got the best integrated performance.


Author(s):  
Matti Kuittinen

Purpose This study investigates the carbon footprint of the alternative structure types and materials used for the reconstruction of schools in Haiti. Are recycled construction materials more environmental than virgin materials? To estimate which alternative construction solution has the smallest carbon footprint, a survey was made for the school model used for the reconstruction programme in Haiti after the 2010 earthquake. Design/methodology/approach The carbon footprint was calculated using life cycle assessment methodology for five different concrete structure alternatives and five different cement mixes for the same design of a school building. In addition, the uptake of CO2 through the carbonation of concrete during 50 years was calculated. Findings The carbon footprint of recycled materials can be either the best or worst option, depending on how the materials are used. The difference to using virgin materials is not big. This is mainly due to the lower structural performance of recycled materials, which needs to be compensated for by using additional reinforcements. Using cement mixes that have high amounts of substitutes for cement seems to lower the carbon footprint of structures considerably. The uptake of CO2 in carbonation has potential but requires an optimal design and environment. Originality/value The findings give information for humanitarian project managers and designers on lowering the carbon footprint of their construction projects.


2020 ◽  
Vol 70 (2) ◽  
pp. 197-211
Author(s):  
Žiaran Stanislav ◽  
Šooš Ľubomír ◽  
Chlebo Ondrej

AbstractThe aim of the article is to define the conditions for the use of recycled resilient materials in the reduction of noise and vibration as an integral part of the mounting and installation of mechanical systems in the work and natural environment. Based on the frequency spectrum, the vibro-isolation efficiency of the vibro-isolators and the viscoelastic materials used is analysed. The solution of this problem is based on the theoretical knowledge and methodology of the transmission of vibration-sound waves. The measurements of the vibration at the sources and along the path of transmission were performed for different recycled materials to compare experimental results with theory.


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