Construction Practices of Short Paneled Concrete Pavements (SPCP) for High Volume Roads

2021 ◽  
Author(s):  
Sridhar Kasu ◽  
Amaranatha Mupireddy ◽  
Nilanjan Mitra
Keyword(s):  
Large Scale ◽  
Plain Concrete ◽  
High Volume ◽  
Concrete Pavements ◽  
Joint Spacing ◽  
Initial Cost ◽  
The Usa ◽  
Scale Test ◽  
State Of Research

The state of research on narrow and non-dowel short jointed paneled concrete pavements (SPCP) is gaining attention on a large scale across the different parts of the world especially in Chile, the USA, and India. The jointed plain concrete pavements (JPCP), which are designed with slab sizes around 3.5 m x 4.5 m results in thicker slabs with a thickness of paving quality concrete (PQC) layer ranging from 280-330 mm depending on load and temperature stresses on Indian highways. In addition to thicker slabs, JPCP requires dowelled joints, which increases the initial cost of pavement. In order to reduce the thickness and initial cost of construction, the use of cast-in-situ SPCP laid on a strong foundation consisting of a dry lean concrete (DLC) base, cement treated sub base (CTSB) and subgrade is being studied. The square short slabs of size: 1 m, 1.5 m and 2 m joint spacing and of thickness 180 to 220 mm were designed and constructed as two full-scale test sections of SPCP on national highways (NH-2 and NH-33) in India. Slabs were constructed by introducing an initial vertical saw-cut of 3 to 5 mm wide and to a depth of 1/4th to 1/3rd of the thickness. The adopted construction practices through field demonstration and implication of SPCP for highways is the main thrust of the paper which helps the practitioners, designers for adopting such projects in the future.

Performance evaluation of jointed plain concrete pavements with sealed and unsealed joints in North Texas

2019 ◽  
Vol 46 (7) ◽  
pp. 601-608
Author(s):  
Mena I. Souliman ◽  
Ashish Tripathi ◽  
Lubinda F. Walubita ◽  
Mayzan M. Isied
Keyword(s):  
Field Performance ◽  
Plain Concrete ◽  
Water Infiltration ◽  
Concrete Pavements ◽  
North Texas ◽  
Pavement Distress ◽  
Initial Cost ◽  
Additional Costs ◽  
Cost Of Construction

Joint sealing in jointed plain concrete pavement (JPCP) has been practiced throughout the world for many years as it improves the performance of concrete pavements. The infiltration of water is a common problem in concrete pavements and often increases distresses, such as faulting and pumping. For this reason, sealing the joints can help reduce water infiltration. Additionally, the infiltration of sand and small stones, aggregates, or debris into the joints can also be prevented, consequently reducing joint spalling in concrete pavements. However, it is also reported that joint sealing increases the initial cost of construction, especially if the joints need to be resealed, which leads to some additional costs. In this study, the pavement distress data was collected from the long-term pavement performance (LTPP) database for all the JPCPs sections in North Texas. The study illustrates the relative field performance in terms of spalling, faulting, roughness, and deflections of JPCP sections for both sealed and unsealed LTPP sections of North Texas.

Thermo-hydro-mechanical simulation of ATLAS in situ large scale test in Boom Clay

2009 ◽  
Vol 36 (4) ◽  
pp. 626-640 ◽  
Author(s):  
Bertrand François ◽  
Lyesse Laloui ◽  
Clément Laurent
Keyword(s):  
Large Scale ◽  
Boom Clay ◽  
Mechanical Simulation ◽  
Scale Test

Innovative test method for the reliable evaluation of joint sealants in concrete pavements

2021 ◽  
Author(s):  
David Ov ◽  
Rolf Breitenbücher ◽  
Martin Radenberg ◽  
Dominik Twer
Keyword(s):  
Plain Concrete ◽  
Test Method ◽  
Life Cycle Costs ◽  
Artificial Ageing ◽  
Concrete Pavements ◽  
Joint System ◽  
Relevant Element ◽  
Reliable Correlation

Joint sealants as indispensable filling systems in jointed plain concrete pavements (JPCP) are permanently exposed to various stresses during their service life, which often leads to a replacement of the sealing after approx. 7 to 10 years. Aside from seasonal unsteady climatic changes, the cyclical stresses caused by traffic and the ageing of joint sealants are especially significant. Considering the rising number of damages that occur within the overall "joint" system, an increased demand for a durable solution is requested as it is a relevant element for the life cycle costs of concrete pavements. In this context, a testing and ageing method was developed which comprises of the entire "joint" system, including the saw-cut concrete joint flanks, the primer as well as the joint sealant. This procedure depicts the decisive scenarios of in-situ stresses and allows the characterization of joint sealants. For this purpose, specimens were subjected to horizontal and vertical loads (static/cyclic) as well as to various ageing effects (temperature conditioning, UV-conditioning and freeze-thaw-cycles). After conditioning, a significant influence of the artificial ageing on the residual strength was observed in the tensile/shear tests. By comparing the artificially aged samples tested in the laboratory with extracted and in-situ aged samples, a reliable correlation was determined. Considering these system tests an initial approach was established which enables the evaluation of joint sealants in both unaged and artificially aged conditions on the basis of scientific parameters and limits.

Thin Concrete Overlays with Carbon Reinforcement

2021 ◽  
Author(s):  
Julia Neumann ◽  
Kristina Farwig ◽  
Rolf Breitenbücher ◽  
Manfred Curbach
Keyword(s):  
Large Scale ◽  
Plain Concrete ◽  
Bottom Layer ◽  
Concrete Pavements ◽  
Flexural Stress ◽  
Bond Behaviour ◽  
Concrete Overlays ◽  
Flexural Tensile Strength ◽  
Major Disadvantage ◽  
The One

In many countries like Germany, concrete pavements are normally built as Jointed Plain Concrete Pavements (JPCP). Due to a lack of alternatives, maintenance of concrete pavements usually requires a replacement of the whole pavement structure, which is labour- and resource-intensive. Therefore, new techniques like the application of thin concrete overlays as a partial repair of deteriorated concrete pavements have been developed. As a major disadvantage of such overlays, the existing joints in the retained concrete bottom-layer have to be transferred in the overlay in order to avoid reflection cracking. When using non-corrosive carbon-textile reinforcement in such concrete overlays, cracks might be distributed more finely, enabling jointless repairs while keeping a thin repair layer. In addition, the bond behaviour between the retained concrete and the applied concrete overlay as well as between the concrete overlay and the textile reinforcement is crucial for a successful repair. In this paper, the basic principles and feasibility of such a repair method are examined. On the one hand, the decisive influencing variables and parameters such as bond behaviour between the concrete layers and the cracking behaviour of the overlay are pointed out and discussed. On the other hand, the evaluated laboratory tests carried out are presented. These include large-scale beams built with an overlay on top of a retained concrete layer, which were subjected to cyclic flexural stress and to a subsequent detailed investigation of the bond behaviour and durability. Furthermore, the crack formation in the overlay was determined by means of tensile and flexural tensile strength tests.

Transverse Cracking Distress in Long-Term Pavement Performance Jointed Concrete Pavement Sections

1998 ◽  
Vol 1629 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Eric D. Moody
Keyword(s):  
Prediction Models ◽  
Plain Concrete ◽  
Pavement Performance ◽  
Complete Analysis ◽  
Concrete Pavements ◽  
Joint Spacing ◽  
Transverse Cracking ◽  
Design Variables ◽  
Jointed Concrete Pavement

Transverse cracking is one of the more common distress manifestations in jointed concrete pavements. While the extent of transverse cracking is largely related to the specified joint spacing, there are several other primary design variables and distress mechanisms that can cause varying degrees of transverse cracking. These primary mechanisms and their associated variables are well-documented in the literature. However, all of these mechanisms often work on the pavement simultaneously over many years and, as a result, it has historically been difficult to calibrate prediction models with field data. The Strategic Highway Research Program’s Long-Term Pavement Performance (LTPP) program has collected a significant amount of condition survey data on more than 110 jointed plain concrete pavements (JPCP) and 65 jointed reinforced concrete pavements (JRCP) throughout North America over the last 7 years. The occurrence of transverse cracking in these sections is one of the principal distresses documented in the condition surveys and therefore provides an excellent data source for examining the relationships between the various primary distress mechanisms and the actual occurrence of distress in the field. Although it is premature to develop or calibrate purely “mechanistic” models based on the LTPP data, enough data have been collected to begin analyzing this distress and its association with the numerous prediction variables in the LTPP database. A complete analysis of the transverse cracking that has occurred in these LTPP test sections, along with their respective relationships with the primary prediction variables found in the primary distress mechanisms, is provided.

Age Advantages of Emotional Experience during the COVID-19 Pandemic are Robust, but Diminished Compared to Pre-pandemic Conditions

2020 ◽  
Author(s):  
Rui Sun ◽  
Disa Sauter
Keyword(s):  
Older Adults ◽  
Large Scale ◽  
Negative Emotion ◽  
Emotional Experience ◽  
Negative Emotions ◽  
Older Individuals ◽  
Selection Strategies ◽  
Scale Test ◽  
Prolonged Stress

Getting old is generally seen as unappealing, yet aging confers considerable advantages in several psychological domains (North & Fiske, 2015). In particular, older adults are better off emotionally than younger adults, with aging associated with the so-called “age advantages,” that is, more positive and less negative emotional experiences (Carstensen et al., 2011). Although the age advantages are well established, it is less clear whether they occur under conditions of prolonged stress. In a recent study, Carstensen et al (2020) demonstrated that the age advantages persist during the COVID-19 pandemic, suggesting that older adults are able to utilise cognitive and behavioural strategies to ameliorate even sustained stress. Here, we build on Carstensen and colleagues’ work with two studies. In Study 1, we provide a large-scale test of the robustness of Carstensen and colleagues’ finding that older individuals experience more positive and less negative emotions during the COVID-19 pandemic. We measured positive and negative emotions along with age information in 23,629 participants in 63 countries in April-May 2020. In Study 2, we provide a comparison of the age advantages using representative samples collected before and during the COVID-19 pandemic. We demonstrate that older people experience less negative emotion than younger people during the prolonged stress of the COVID-19 pandemic. However, the advantage of older adults was diminished during the pandemic, pointing to a likely role of older adults use of situation selection strategies (Charles, 2010).

scholarly journals IMPROVING SYSTEM READINESS, STAFF PREPAREDNESS AND PATIENT SAFETY IN A NEW SINGLE FAMILY ROOM NICU THROUGH IN SITU SIMULATION

2018 ◽  
Vol 23 (suppl_1) ◽  
pp. e16-e16
Author(s):  
Ahmed Moussa ◽  
Audrey Larone-Juneau ◽  
Laura Fazilleau ◽  
Marie-Eve Rochon ◽  
Justine Giroux ◽  
...  
Keyword(s):  
Patient Safety ◽  
Repeated Measures ◽  
Large Scale ◽  
Multidisciplinary Teams ◽  
Single Family ◽  
In Situ Simulation ◽  
Ensure Patient Safety ◽  
System Readiness ◽  
Dependent Samples

Abstract BACKGROUND Transitions to new healthcare environments can negatively impact patient care and threaten patient safety. Immersive in situ simulation conducted in newly constructed single family room (SFR) Neonatal Intensive Care Units (NICUs) prior to occupancy, has been shown to be effective in testing new environments and identifying latent safety threats (LSTs). These simulations overlay human factors to identify LSTs as new and existing process and systems are implemented in the new environment OBJECTIVES We aimed to demonstrate that large-scale, immersive, in situ simulation prior to the transition to a new SFR NICU improves: 1) systems readiness, 2) staff preparedness, 3) patient safety, 4) staff comfort with simulation, and 5) staff attitude towards culture change. DESIGN/METHODS Multidisciplinary teams of neonatal healthcare providers (HCP) and parents of former NICU patients participated in large-scale, immersive in-situ simulations conducted in the new NICU prior to occupancy. One eighth of the NICU was outfitted with equipment and mannequins and staff performed in their native roles. Multidisciplinary debriefings, which included parents, were conducted immediately after simulations to identify LSTs. Through an iterative process issues were resolved and additional simulations conducted. Debriefings were documented and debriefing transcripts transcribed and LSTs classified using qualitative methods. To assess systems readiness and staff preparedness for transition into the new NICU, HCPs completed surveys prior to transition, post-simulation and post-transition. Systems readiness and staff preparedness were rated on a 5-point Likert scale. Average survey responses were analyzed using dependent samples t-tests and repeated measures ANOVAs. RESULTS One hundred eight HCPs and 24 parents participated in six half-day simulation sessions. A total of 75 LSTs were identified and were categorized into eight themes: 1) work organization, 2) orientation and parent wayfinding, 3) communication devices/systems, 4) nursing and resuscitation equipment, 5) ergonomics, 6) parent comfort; 7) work processes, and 8) interdepartmental interactions. Prior to the transition to the new NICU, 76% of the LSTs were resolved. Survey response rate was 31%, 16%, 7% for baseline, post-simulation and post-move surveys, respectively. System readiness at baseline was 1.3/5,. Post-simulation systems readiness was 3.5/5 (p = 0.0001) and post-transition was 3.9/5 (p = 0.02). Staff preparedness at baseline was 1.4/5. Staff preparedness post-simulation was 3.3/5 (p = 0.006) and post-transition was 3.9/5 (p = 0.03). CONCLUSION Large-scale, immersive in situ simulation is a feasible and effective methodology for identifying LSTs, improving systems readiness and staff preparedness in a new SFR NICU prior to occupancy. However, to optimize patient safety, identified LSTs must be mitigated prior to occupancy. Coordinating large-scale simulations is worth the time and cost investment necessary to optimize systems and ensure patient safety prior to transition to a new SFR NICU.

Sign in / Sign up

Export Citation Format

Share Document