Basic Info.
Model NO.
All standards glass beads for roadmarking
Main Raw Material
Nano Oxide
Certification
ISO14001, RoHS, ISO9001
Transport Package
25kgs, 500kgs, 1000kgs
Specification
Bs 6088, Ks, En and So on
Product Description
For an effective thermoplastic pavement marking replacement strategy, the rate at which the marking's retro-reflectivity deteriorates in service must be well established in order to avoid re-stripping that is too soon or too late. Against this background, this paper undertook a review of models that deal with degradation of thermoplastic pavement markings under different traffic and environmental conditions in order to establish service life and the terminal retro-reflectivity levels that have informed re-striping. Service life in the context of this paper is the time taken for a newly-installed marking to degrade to some minimum retro-reflectivity level below which motorists would find it difficult to navigate on the carriageway under night-time and poor visibility conditions. It was established that the minimum retro-reflectivity requiring re-stripping intervention reported varied, although commonly-adopted values tended to range from 50 mcd/m2 /lx to 150 mcd/m2 /lx. A number of empirical models, based on site specific conditions, have been developed by researchers using field data, to estimate marking retro-reflectivity at any time since placement. Whereas some of the models used time as the only independent variable, others used a combination of time, traffic level and a few other parameters to estimate retro-reflectivity. Even though degradation of marking retro-reflectivity is a reflection, among other things of material degeneration impacted by environmental and service conditions, almost all the models reviewed failed to consider environmental factors. Additionally, for some of the models, non-inclusion of the initial retro-reflectivity level and their generally low coefficient of determination statistic erode the confidence in their reliability.Degradation, Re-Striping, Retro-Reflectivity, Service Life, Thermoplastic Pavement Marking- Introduction
Retro-reflective pavement markings are used as key visual elements to guide motorists when roadway visibility is compromised by night-time and adverse weatherconditions in order to help drivers keep their position on the carriageway and avoid lane departure accidents. The ability of pavement markings to retro-reflect headlamp illumination begins to decline following marking installation due to several factors that operate within the service environment and, with time, may be lost completely. Factors that cause deterioration in marking retro-reflectivity are varied but may include bead loss, loss of base material due to chipping and abrasion, deposition of detritus on the marking, discoloration of paint material and loss of contrast between the base material and its surrounding . In order that they will continue to provide navigation guidance to motorists, pavement markings should be scheduled for maintenance when they reach some minimum threshold in retro-reflectivity . This pre-supposes that the Transportation Department or Road Agency concerned has information about the minimum retro-reflectivity level found acceptable to motorists within its area of jurisdiction and that a methodology exists for establishing the service life of the marking so as to avoid replacement that is too soon or too late. In the context of this paper, service life is the time taken by a newly-placed thermoplastic pavement marking to degrade to a pre-determined minimum retro-reflectivity level below which motorists would find it difficult to navigate on the carriageway under night-time and poor visibility conditions .
It is recognized that because of the varied operational environments within which pavement markings function, it may be difficult to find a single deterioration model of universal applicability to guide re-stripping interventions. A simple approach is to estimate the service life of a marking based on the past performance of similar materials or to undertake periodic retro-reflectivity measurements. Under limited budget, the latter approach may make it difficult for the management of pavement markings. There is, therefore, a clear need for a more rigorous methodology to define and predict the service life of a pavement marking within its service environment. Against this background, this paper undertook a review of models that have been used by researchers to deal with degradation of thermoplastic pavement markings under different traffic and environmental conditions and the terminal retro-reflectivity levels that have informed re-striping. The intention was to define a pathway to further studies into pavement marking retro-reflectivity degradation as impacted by the service environment.2. Minimum Acceptable Retro-Reflectivity
The service life of retro-reflective pavement markings is defined as the time taken for a newly-installed marking to degrade to some minimum retro-reflectivity level below which motorists would find it difficult to navigate on the carriageway under night-time and poor visibility conditions. Even though marking performance may be based on both durability and visibility, it is visibility which defines the lower limit of the acceptable performance range and, hence, the point at which re-stripping intervention is required. Transportation Departments may set their own standards that meet the visibility needs of the range of drivers using their road networks based on driver subjective ratings of pavement markings under night-time conditions. In principle, minimum retro-reflectivity is dictated by driver preview distance requirements which are speed-dependent. At higher speeds, longer viewing distances are required which in turn require higher levels of pavement retro-reflectivity . While control can be exercised on the initial retro-reflectivity level through manipulation of paint characteristics, reflective beads content and material at the marking stage, terminal values are dependent on the minimum found acceptable to motorists under night-time conditions.
Research works on marking retro-reflectivity reported in literature have used different minimum values in dealing with marking degradation. Minimum values which ranged from 85 to 150 mcd/m2/lx were used by Migletz et al. in some parts of the United States to study white and yellow thermoplastic marking degradation. Sarasua and Bell , Andrady and Fitch and Ahearn used 100 mcd/m2/lx as the minimum to guide marking degradation model development. Others, such as Abboud and Bowman and Chimba et al. have used a much higher value of 150 mcd/m2/lx in retro-reflectivity degradation studies.
.
To improve road safety in the United States, the Federal Highway Administration (FHWA) has proposed updates to minimum retro-reflectivity values in the Manual on Uniform Traffic Control Devices (MUTCD) that set 50 mcd/m2/lx and 100 mcd/m2/lx for posted speed limits of 35 mi/h (56.4 km/h) or greater and 70 mi/h (112.7 km/h) or greater, respectively . In some transportation jurisdictions, for example , markings having retro-reflectivity levels less than 60 mcd/m2/lx are considered bad and require immediate renewal and in Ghana, Salifu and Owusu established a minimum standard of 150 mcd/m2/lx for highways in the country based on subjective ratings of markings by drivers during nighttime driving.
3. Empirical Marking Degradation Models
The coated glass bead have been treated with high quality organic materials on their surface, thus bearing better features in quality. Our company has developed this unique product after absorbing advanced technology from foreign countries and it has the following advantageous features:
A The contrary reflexible of the micro glass beads maintains since we select the materials which are similar to the nature of micro glass beads.
B In rainy and wet weather, ordinary glass beads would be surrounded by water and result in th low reflection rate. However, the micro beads with coated can maintain the reflection effect to a great extent.
C Ordinary glass beads would pile up in the sprayer after absorbing water. However, micro beads with coated would not so, thus increasing the working efficiency.
D Since micro beads with coated contain special adhesives, thus improving the integrity between the micro beads and the paints.
E Can prevent sinking of micro beads to the bottom of paints.
F After the treatment of coated thus absorbing less dust from air.
Product specification
Coated can be done from 50μ M-1180μ M, based on clients requirements.
Technical references
Appearance: Beads with round ball shape and no visible impurity.
Refractive index: >1.5
Density: 2.4-2.6g/cm3
SiO2 content: ≥ 68%
Size distribution and spherical beads.
Address:
Mengcun,Yangshuiwu Town, An′ci District, Langfang, Hebei, China
Business Type:
Manufacturer/Factory, Trading Company
Business Range:
Arts & Crafts, Chemicals, Industrial Equipment & Components, Instruments & Meters, Lights & Lighting, Tools & Hardware
Management System Certification:
ISO 9001, OHSAS/ OHSMS 18001
Company Introduction:
Langfang Daohong Glass Beads Co., Ltd is a professional glass beads company. We annually produce 15, 000 tons glass beads. Its products are widely used in a variety of highway construction projects, and export to the United States, Britain, Canada, Europe and Japan, South Korea, Thailand, Malaysia, Indonesia and other Southeast Asian countries, we were endorsed unanimously by customers at home and abroad.
We are the manufacturer of glass beads for road marking paint in China. We can supply all kinds of glass beads for road marking paint, for example BS 6088, ks I, ksii, aashto m 247, en 1423, en1424 and so on. Our product has high quality and good price, there are 2 pictures about our packing in the attachment.
We are happy to keep in touch with you.
Langfang Daohong Glass Beads Co., Ltd is a professional glass beads company. We annually produce 15, 000 tons glass beads. We have certificated by ISO, SGS and CE. As Alibaba and Made-In-China GOOD SUPPLIER we authenticated by China Ministry of Transportation at the same time.
Our products: Sand blasting glass beads, road marking glass beads, decorated irregular color glass beads, grinding glass beads.
We have clients come from United States, Britain, Canada, Europe and Japan, South Korea, Thailand, Malaysia, Indonesia, Kenya and Middle East countries, we were endorsed unanimously by customers at home and abroad.