Influence of reclaimed materials on base course quality

2012 ◽  
pp. 566-571
Author(s):  
K Kubo ◽  
M Itani ◽  
S Horiuchi
Keyword(s):  
Course Quality ◽  
Base Course

Cement Content of Durability Cement Stabilized Macadam Base Course in Seasonal Freezing Zone

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Junchen Ma ◽  
Chunyu Liang ◽  
Ying Wang ◽  
Lidong Zhang ◽  
Weiwu Cui ◽  
...  
Keyword(s):  
Cement Content ◽  
Seasonal Freezing ◽  
Base Course

scholarly journals Studies on the Volumetric Stability and Mechanical Properties of Cement-Fly-Ash-Stabilized Steel Slag

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 495
Author(s):  
Mingkai Zhou ◽  
Xu Cheng ◽  
Xiao Chen
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Steel Slag ◽  
Critical Issue ◽  
Expansion Behavior ◽  
Strength Tests ◽  
Road Materials ◽  
Base Course ◽  
The Stability ◽  
Aggregate Base

The stability of steel-slag road materials remains a critical issue in their utilization as an aggregate base course. In this pursuit, the present study was envisaged to investigate the effects of fly ash on the mechanical properties and expansion behavior of cement-fly-ash-stabilized steel slag. Strength tests and expansion tests of the cement-fly-ash-stabilized steel slag with varying additions of fly ash were carried out. The results indicate that the cement-fly-ash-stabilized steel slag exhibited good mechanical properties. The expansion rate and the number of bulges of the stabilized material reduced with an increase in the addition. When the addition of fly ash was 30–60%, the stabilized material was not damaged due to expansion. Furthermore, the results of X-CT, XRD and SEM-EDS show that fly ash reacted with the expansive component of the steel slag. In addition, the macro structure of the stabilized material was found to be changed by an increase in the concentration of the fly ash, in order to improve the volumetric stability. Our study shows that the cement-fly-ash-stabilized steel slag exhibits good mechanical properties and volumetric stability with reasonable additions of fly ash.

scholarly journals The Limestone as a Materials Combination of Base Course on the Road Pavement

2021 ◽  
Vol 1125 (1) ◽  
pp. 012019
Author(s):  
Yosef Cahyo Setianto Poernomo ◽  
Sigit Winarto ◽  
Zendy Bima Mahardana ◽  
Dwifi Aprillia Karisma ◽  
Rekso Ajiono
Keyword(s):  
The Road ◽  
Road Pavement ◽  
Base Course ◽  
On The Road

scholarly journals REAPing the benefits: development and use of a structured evaluation framework to codify learning resources for Global Health professionals

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Meike Schleiff ◽  
Elizabeth Hahn ◽  
Caroline Dolive ◽  
Lillian James ◽  
Anant Mishra ◽  
...  
Keyword(s):  
Global Health ◽  
Health Professionals ◽  
Learning Opportunities ◽  
Evaluation Framework ◽  
Course Quality ◽  
Health Leadership ◽  
Wide Range ◽  
Meaningful Engagement ◽  
Online Activities ◽  
Competency Domains

Abstract Background The learning opportunities for global health professionals have expanded rapidly in recent years. The diverse array of learners and wide range in course quality underscore the need for an improved course vetting process to better match learners with appropriate learning opportunities. Methods We developed a framework to assess overall course quality by determining performance across four defined domains Relevance, Engagement, Access, and Pedagogy (REAP). We applied this framework across a learning catalogue developed for participants enrolled in the Sustaining Technical and Analytic Resources (STAR) project, a global health leadership training program. Results The STAR learning activities database included a total of 382 courses, workshops, and web-based resources which fulfilled 531 competencies across three levels: core, content, and skill. Relevance: The majority of activities were at an understanding or practicing level across all competency domains (486/531, 91.5%). Engagement: Many activities lacked any peer engagement (202/531, 38.0%) and had limited to no faculty engagement (260/531, 49.0%). Access: The plurality of courses across competencies were offered on demand (227/531, 42.7%) and were highly flexible in pace (240/531, 45.2%). Pedagogy: Of the activities that included an assessment, most matched activity learning objectives (217/531, 40.9%). Conclusions Through applying REAP to the STAR project learning catalogue, we found many online activities lacked meaningful engagement with faculty and peers. Further development of structured online activities providing learners with flexibility in access, a range of levels of advancement for content, and opportunities to engage and apply learning are needed for the field of global health.

Precast Pavement Smoothness Control Method

2014 ◽  
Vol 587-589 ◽  
pp. 1071-1074 ◽  
Author(s):  
Peng Peng ◽  
De Fen Wu ◽  
Bo Tian ◽  
Kai Min Niu
Keyword(s):  
Control Method ◽  
Control Measure ◽  
Road Maintenance ◽  
Precision Control ◽  
Service Effectiveness ◽  
Base Course

In the course of road maintenance, importance has been gradually attached by administrative authorities to precast pavement for its advantages like quickness, endurance and eco-friendliness. To ensure the smoothness of precast pavement, analyses and researches were done in terms of, say, precast pavement slab precision control, base course treatment, fabricated pavement slab leveling and treatment of joint faulting, and a control measure to ensure and improve the smoothness of precast pavement is suggested with consideration given to its service effectiveness in actual projects.

The Influence of Different Subbase Materials on the Crack of Cement Stabilized Macadam Base during Construction

2012 ◽  
Vol 591-593 ◽  
pp. 955-959 ◽  
Author(s):  
Xiao Feng Liao ◽  
Fen Xiao ◽  
Zhong Da Chen ◽  
Lei Xing
Keyword(s):  
Tensile Stress ◽  
Shrinkage Strain ◽  
Mechanical Parameters ◽  
Tensile Stresses ◽  
Shrinkage Crack ◽  
Dry Shrinkage ◽  
Base Course ◽  
Shrinkage Coefficient ◽  
Crack Space

According to actual axle load data and the measured mechanical parameters of cement stabilized macadam material with different cement dosages, the bottom tensile stresses of different subbase structures are calculated and the results show that: to graded gravel subbase, the weight of construction vehicle is inadvisable to be more than 35t and the cement dosage of base course shall be more than 3.0%; and, the maximum bottom tensile stress of graded gravel subbase shall be much more than that of lime-flyash soil subbase. According to the measured dry shrinkage strain and dry shrinkage coefficient, the dry shrinkage crack space of base course is analyzed and the results show that: under the same cement dosage, the crack space of the base course with graded gravel subbase is smaller than that of lime-flyash soil subbase; with the increase of cement dosage, the crack space of base course increase first and then decrease, and when the cement dosage is 3.5%, the dry shrinkage strain and dry shrinkage coefficient is minimum and the crack space of base course is maximum.

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