A Users Guide to Performance Engineered Mixtures

2021 ◽  
Author(s):  
Jim Grove ◽  
Michael Praul ◽  
Jagan Gudimettla ◽  
Robert Conway ◽  
Peter Taylor
Keyword(s):  
Quality Control ◽  
Concrete Pavement ◽  
Comprehensive Approach ◽  
Robust Approach ◽  
Technology Center ◽  
The Past ◽  
Concrete Properties ◽  
Federal Highway ◽  
Departments Of Transportation ◽  
Three Components

Performance Engineered Mixtures is an initiative, spearheaded by the Federal Highway Administration and the National Concrete Pavement Technology Center, in cooperation with state Departments of Transportation and the concrete paving industry, to develop a comprehensive approach to modernizing the way concrete is specified, tested, and accepted. It focusses on three components: testing of six critical concrete properties, a robust approach to quality control, and the replacement of prescriptive specifications. Many new tests have been recently developed that provide the ability to test concrete properties more easily and quicker than in the past. This paper provides background of how this initiative began. It elaborates on each of the six properties of concrete that are the focus of PEM. The new tests that are integral to the PEM process are described. The effects PEM will have on the acceptance process and the quality control responsibilities are outlined. Finally, tables are included which list the properties and the tests that are associated with each property, as well as how each is applied to each step of the paving process.

Determination of Sample Size and Influencing Factors to Characterize Faulting in Jointed Concrete Pavements

2021 ◽  
pp. 036119812199670
Author(s):  
Ruohan Li ◽  
Jorge A. Prozzi
Keyword(s):  
Sample Size ◽  
Plain Concrete ◽  
Concrete Pavements ◽  
Portland Cement Concrete ◽  
Federal Highway ◽  
Significant Difference ◽  
Jointed Concrete Pavement ◽  
Functional Classes ◽  
High Precipitation ◽  
Departments Of Transportation

The objective of this study is to evaluate the field variability of jointed concrete pavement (JCP) faulting and its effects on pavement performance. The standard deviation of faulting along both the longitudinal and transverse directions are calculated. Based on these, the overall variability is determined, and the required sample sizes needed for a given precision at a certain confidence level are calculated and presented. This calculation is very important as state departments of transportation are required to report faulting every 0.1 mi to the Federal Highway Administration as required by the 2015 FAST Act. On average, twice the number of measurements are needed on jointed reinforced concrete pavements (JRCP) to achieve the same confidence and precision as on jointed plain concrete pavements (JPCP). For example, a sample size of 13 is needed to achieve a 95% confidence interval with a precision of 1.0 mm for average faulting of JPCP, while 26 measurements are required for JRCP ones. Average faulting was found to correlate with several climatic, structural, and traffic variables, while no significant difference was found between edge and outer wheelpath measurements. The application of Portland cement concrete overlay and the use of dowel bars (rather than aggregate interlock) are found to significantly reduce faulting. Older sections located on higher functional classes, and in regions of high precipitation or where the daily temperature change is larger, tend to have higher faulting, and might require larger samples sizes as compared with the rest when faulting surveys are to be conducted.

Proctorship in Minimally Invasive Colorectal Surgery

2021 ◽  
Vol 34 (03) ◽  
pp. 186-193
Author(s):  
Assad Zahid ◽  
Danilo Miskovic
Keyword(s):  
Quality Control ◽  
Colorectal Surgery ◽  
Minimally Invasive ◽  
Emerging Technology ◽  
Specific Technique ◽  
Novel Technique ◽  
The Past ◽  
Or Groups ◽  
Minimally Invasive Colorectal Surgery ◽  
Teaching Programs

AbstractTeaching an established surgeon in a novel technique by a colleague who has acquired a level of expertise is often referred to as “proctoring” or “precepting.” Surgical preceptorships can be defined as supervised teaching programs, whereby individual or groups of surgeons (proctors) experienced in a certain technique support a colleague who wants to adopt this technique (sometimes referred to as “delegates” or “preceptees”). Preceptorship programs really focus on a specific technique, technology, or skill which is required to broaden, complement, or transform an established surgeon's practice.Within colorectal surgery, in the past 30 years, there is been an evolution of interventional options including open, laparoscopic, robotic, and endoscopic procedures. With each new emerging technology and technique, safe and effective uptake by established surgeons is best been attained by a period of proctorship by an experienced colleague. Formalizing this has been facilitated largely through industry support. There, however, remains a considerable chasm when it comes to standardization, quality control, and jurisprudence.This article aims to describe the requirements for a contemporary proctorship program, to examine instruments of quality control, and how to improve effectiveness.

scholarly journals Recirculating Aquaculture Technologies

2019 ◽  
pp. 35-76 ◽  
Author(s):  
Carlos A. Espinal ◽  
Daniel Matulić
Keyword(s):  
Water Quality ◽  
Quality Control ◽  
Wastewater Treatment ◽  
Water Quality Control ◽  
New Developments ◽  
The Past ◽  
Control Processes ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems ◽  
Aquaculture Production

AbstractRecirculating aquaculture technology, which includes aquaponics, has been under development for the past 40 years from a combination of technologies derived from the wastewater treatment and aquaculture sectors. Until recently, recirculating aquaculture systems (RAS) farms have been relatively small compared with other types of modern aquaculture production. The last two decades have seen a significant increase in the development of this technology, with increased market acceptance and scale. This chapter provides a brief overview of the history, water quality control processes, new developments and ongoing challenges of RAS.

scholarly journals CONSTRUCTION AND QUALITY CONTROL OF NON-JOINTED POROUS CONCRETE PAVEMENT

1998 ◽  
Vol 3 ◽  
pp. 111-118
Author(s):  
Tosihiro TAKEI ◽  
Osamu KARASAWA ◽  
Teruhiko MARUYAMA
Keyword(s):  
Quality Control ◽  
Concrete Pavement ◽  
Porous Concrete

Curling Stress Equation for Transverse Joint Edge of a Concrete Pavement Slab Based on Finite-Element Method Analysis

1996 ◽  
Vol 1525 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Tatsuo Nishizawa ◽  
Tadashi Fukuda ◽  
Saburo Matsuno ◽  
Kenji Himeno
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fem Analysis ◽  
Concrete Pavement ◽  
Winkler Foundation ◽  
Stress Equation ◽  
The Past ◽  
Transverse Joint ◽  
Foundation Model ◽  
Element Method

In the design of concrete pavement, curling stresses caused by the temperature difference between the top and bottom surfaces of the slab should be calculated at the transverse joint edge in some cases. However, no such equation has been developed in the past. Accordingly, a curling stress equation was developed based on stress analysis using the finite-element method (FEM). In this FEM analysis, a concrete pavement and its transverse joint were expressed by means of a thin plate–Winkler foundation model and a spring joint model, respectively. Multiregression analysis was applied to the results of the FEM numerical calculation and, consequently, a curling stress equation was obtained. After comparing the calculated results of the equation with curling stress equations developed in the past, it was confirmed that the equation was valid and practical.

Quality Control Procedures for Underwater Inspections

2005 ◽  
Vol 1933 (1) ◽  
pp. 9-14
Author(s):  
Jeffrey B. Rowe
Keyword(s):  
Quality Control ◽  
Control Measures ◽  
Policies And Procedures ◽  
Control Procedures ◽  
Departments Of Transportation

For more than 20 years, the FHWA has required that underwater inspection of bridges be performed at least every 5 years. Over that period, departments of transportation and other bridge owners have either developed in-house underwater inspection teams or hired outside consultants to perform this work. Ensuring that the inspections are conducted properly and accurately is critical. To this end, several policies and procedures can be implemented as quality control measures in an underwater inspection program. Selecting a properly trained inspection team, ensuring proper preparation before diving operations, conducting independent inspections, and looking at deterioration trends are several ways to ensure quality in underwater inspections.

Quality Management in Textile through Noble Methodology and Six Sigma

2011 ◽  
Vol 332-334 ◽  
pp. 351-355
Author(s):  
Seyed Ehsan Hosseinipour ◽  
Mohamad Reza Ahmadzadeh ◽  
Bahareh Zanjirchi
Keyword(s):  
Quality Control ◽  
Quality Management ◽  
Six Sigma ◽  
The Other ◽  
High Quality ◽  
The Past ◽  
Other Hand ◽  
Textile Industries ◽  
Textile Products

In recent decades, different concepts in quality management in textile industries have been introduced. Quality is a highly significant concept and also is the most basic challenge for textile industries. What we called controlling in the past, now has been replaced by “quality control”. Among these strategies, production and noble thought in order to recognize and remove not valuable resources on one hand, and six sigma in order to recognize and remove error elements in the process on the other hand, have developed the textile factories. Six sigma and noble methodology are two very strong strategies in for textile companies to reach success and have high quality products. Noble methodology causes a cut in the expenses through optimizing the process whereas six sigma is related to the customers’ expectations or needs. It also improves quality through measuring and controlling the deficits. This study is an attempt to improve textile products through two views: six sigma and noble methodology. Each of them this objective by its own .

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