Measures on Improving the Mechanical Properties and Construction

Standards of Highway

Yancang Jiang

Department of architecture and civil Engineering

Puyang vocational and technical college,

Puyang, China

pyjgjyc@163.com

Keywords: Highway, Mechanical Properties, Construction Standards, Life, Measures

Abstract. Currently, there are so many heavy vehicles being driven fast and overloading on highway.

Carrying capacity of highway are not fit with this situation, They are often run in a serious state of

overloading and fatigue. This directly influenced the life of highway. So, to improve the mechanical

properties and carrying capacity of highway, and to construction high standard, high speed,

large-tonnage, long-life modern highway are urgent and imperative. This article analyzes the current

traffic load and design, materials select and construction status of highway, and proposed some

measures to improve mechanical properties and construction standards of highway. Life of highway

can be greatly improved by adopt these measures.

Introduction

Currently, highway traffic was developed by leaps and bounds, and growing on an unprecedented

scale. This greatly facilitated people's work, study and life, and effectively promoted rapid

development of the national economy and various undertakings. But in recent years, the service life of

highway was obviously reduced, times and cost of maintenance, repair and reconstruction were

significantly increased. So, the overall benefit of highway construction and use was significantly

reduced. To improve the mechanical properties and carrying capacity of highway, and to construction

high standard, high speed, large-tonnage, long-life modern highway are urgent and imperative facing

of large and rapidly increasing demand for highway transport. We urgently need to discuss and

improve properties and construction standard of highway.

Current Status of Highway Analysis

Traffic Load Analysis. At present, expressway and national highway are running basically well in

our country, but using situation of highway especially in county and rural is in unsatisfactory

conditions. With the national economy rapid development and rapid expansion of transport, more and

more vehicles exercise on highway, they are fast and overloading. In these conditions, highway is

often in a state of severe overload fatigue operation[1][2].

According in-depth social wide range investigation, firstly, fast and efficient and high-speed and

large tonnage and large flux of transportation are urgently needed by national construction and

development of modern society, and these are development trends and direction of the world's

transportation. Secondly, in the current highway design, axle limits still not be changed and improved.

However, design load of vehicles increases, number of vehicles doubled increases and vehicles

overload, all of these factors greatly increase rolling intensity and frequency on highway, and lead to

severe fatigue and damage of highway. lastly, operation customers often remake their vehicles to

increase the height and load of vehicles driven by economic interests. In investigation, they say in

order to make money they must remake vehicles and overload because high cost and large overhead of

transport. For example, rated load 8 tons of the original cars modified by increasing load, the actual

Advanced Materials Research Vols. 243-249 (2011) pp 4274-4278Online available since 2011/May/17 at www.scientific.net© (2011) Trans Tech Publications, Switzerlanddoi:10.4028/www.scientific.net/AMR.243-249.4274

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operating load can be up to more than 20 tons, and rated load about 10 tons of the original cars

modified by increasing load, the actual operating load can be up to more than 30 tons. One container

truck actual load can be up to 40 to 50 tons, and coal vehicles i actual load can be up to 100 tons.

Although our state transportation department pays highly attention to overload issues, and makes

unremitting efforts and specialized remediation, the effect is not good. Overloading vehicles are still

driving and continuous operation with a large number. After free passage of highway implementation,

because of the management weakening, overload has not been effectively eliminated, but increased

and enlarged.

In order to reduce transport costs and reduce expenditure on road pricing Some professional

transport customers always select ordinary highways which are not charge but not select expressway

which are chargeable. This is a direct cause of highway traffic density increased significantly, and

caused entire ordinary highways overwhelmed. More seriously, this phenomenon has been

developing and growing.

At the same time, management and maintenance of ordinary are not good and behind time. After

repaired, they will be destroyed by overload vehicles. Phenomenon of bad after repaired and bad with

repaired is very prominent. Life of highway is Shorten obviously. Some highway in country and

villages are damaged more serious because of their low grade design, poor construction quality and

poor management and maintenance. Our country builds special funds to build highways for country

and villages, however these highways were damaged in one year or even a few months or a few days

by large and heave vehicles[1].

In conclusion, actual load and time of rolling of current highway greatly exceeds the carrying

capacity and design standards of the existing highway. This is the major reason of short life of current

highway, and has created a series social consequences and must be solved.

Design, Material and Construction of Highway Analysis. Current highway has short life and poor

condition. This is not directly related to traffic density, large load vehicles, fast vehicles, but also

directly related to design, material and construction of highway. Current highway basically has two

kinds, one is asphalt concrete roads and the other is ordinary cement concrete roads. Construction of

asphalt concrete roads is convenient, fast and low cost, this kind roads always be widely used from

urban to rural. But this kind road has characters of soft surface, easy deformation, concentrate stress,

high strength, easy extremely, easy cracking and easy damaged by water. Construction of ordinary

cement concrete roads is not convenient, not fast and high cost, and mainly used for the city streets

and special and important sections. But this kind of road has characters of high strength surface, good

rigidity, uniform stress transfer, small effect to intensity, not obvious influence by water. So, this kind

road is Stable, durable, and has a long life especially reinforced concrete road.

From design, construction and materials speaking, due to be influenced such as rapid expansion of

construction scale, shortage of material, quickly rise of price, improvement of cost, enterprises pursuit

economic benefits and be influenced by some adverse factors, design, construction and materials of

ordinary highways being simple frequently occurred, and jerry phenomenon is quite serious in recent

years. This phenomenon is common and an industry potential rules for some enterprise to reduce

project cost and improve the economic benefit and create nice profits. Now do some specific analysis

as follows.

Structure Simplified. he structure only includes the surface layer of asphalt concrete, base and lime

cushion, but some traditional and necessary compound floor becomes rare in roads construction.

According to the field investigation and survey, actual construction thickness generally less than 90%

of the design thickness, and force-hearing layer, actual overall thickness, every layer thickness and

density are obvious deficiency. Because highway structure design, thickness and density is the key

factor to decided highway mechanical performance, actual strength and carrying capacity, the bearing

capacity and operation safety coefficient of current ordinary highways are significantly decreased and

relatively lower.

Low Standard of Construction Supervision and Material Select. Principle of quality first has not

been well implemented. Some construction units often take the standard of can be used, reduce

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trouble, cheap, little money to save money, material, quantity and cost of the work. Otherwise, testing

is not standard. some project contractors conceal and undertake false detection. They submit quality

inspection department high-quality materials to finally get qualified test conclusion, but materials

they actually used are not they submit which are qualified but often are low-quality, inferior or even

fake and waste materials. To this, individual departments are also well known, in order not to assume

responsibility, they usually indicated in the test report: the test material sample is qualified. But about

construction materials if they are qualified they almost never supervise and investigate. In the

construction and completion acceptance, similar phenomena often happened.

In conclusion, low standard design and poor construction quality of highway are another major

reasons which lead to highway small bearing capacity and short service life.

Solving Measures

According to above analysis, improve highway construction standards, solve currently traffic

problems, promote the state construction, this is our best choice.

Improve Axle Load Limit. At present, in our country roads and urban road design specification, we

also take 100kN as design axle load standard, Usually think that our country road axis load limit is

100Kn [3]. But, because of overload of vehicles, the actual axle load significantly differs from axle

load of s design. Conservative peaking, actual axle load probably is around 140KN or even higher

according to calculate. Current international highest axle load also limit in 140kN, so we should

improve axle load design standard of ordinary highways facing the country need high-speed

development and reality of severe overloading and long-term poor management.

Improving Life Design Standards. Short-life building is a huge waste of social resources in building

a long life is the greatest conservation. Highway traffic is closely related to nation-building and

people's lives, road transport is bound to slow, stop and increase investment when reconstruction or

each repair. The more reconstruction, the higher cost, the poorer benefit, and the greater impact on the

nation-building. Short life Road is not only a huge waste of social resources, even more seriously

affects the construction of our country, people's lives and development of various undertakings.

Improving design standards and life of ordinary highways is not only the largest resource

conservation, more importantly, effectively ensure that the national construction and normal people's

lives, and promote the cause of the continued rapid development and social harmony Progress,

prosperity and stability, and will get immeasurable overall economic and social benefits.

Increase Overall Thickness. From the perspective of the force, vehicles are heavier, the vertical

force on the road is greater, the effect depth is deeper, so the vertical force is the fundamental basis for

pavement thickness design[4]. Meanwhile, the greater vertical force needs greater thickness of

bearing layer in highway construction, therefore, each layer thickness and overall thickness of

ordinary highways should be increased in the current high-speed, heavy and severe overloading

situation. Specifically, we must take the upper limit of the construction standard on the basis of

improving design level, and determine by scientific research, experiment and practice. In

construction, thickness must fit design standard, and never allow jerry to happen.

Adopt Composite Surface Layer. Asphalt concrete surface has good flexibility, plasticity, ductility,

water repellency, running a small role in an impact and little wear tyre down. However, it has poor

durability, short life when be single used because its lower intensity, easy deformation, weak bending

capacity, lower and concentrated transmission power and strong damage by vehicles. Cement

concrete surface has high strength, good rigidity, good load capacity, uniform force transmission,

good durability and long life, but has disadvantage of serious impact by vehicles, and wear faster. To

solve the single layer shortcomings and insufficiency, we combine both asphalt concrete surface and

cement concrete surface, pavement performance becomes very well by mutual complementation. In

order to set complex surface, the upper layer laid 10cm thick asphalt concrete surface, the sublayer

laid 15 ~ 20cm cement concrete surface, and set plaster layer and coarse grained gravel soil layer at

the same time. When construction, we should increase thickness of surface and completes compaction

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and waterproof work, and must do well engineering geology exploration and roadbed reinforcement

before construction. Its performance and effect will be better if reinforced concrete with asphalt

concrete surface layer were used in important sections when necessary

Intensify Various Highway Construction. In order to reduce ordinary highway traffic pressure and

fatigue, our country should intensify construction of various highway to expand the scope and mileage

of traffic. At the same time, expressway charging standards should be reduce or abolished step by

step.

Improve Construction Quality.

Improve Construction Quality Consciousness. Quality represents a country's image, a spirit of

the nation. "Hundred policy, quality first"[5][6]. Quality is the key factor to success, quality is the

survival of the enterprise, quality is the fundamental guarantee of national construction development

and people's well-being. Has the quality, everything is available,no quality, no development.

Upholding Scientific Development Concept. The scientific development concept is the

centralized embodiment of the world view and the methodology directing. In order to improve

highway construction quality and construction standards, build high-level highway, we must insist on

scientific development concept through the whole process of construction and development of

highway, and every aspect including elaborate design and scientific construction.

Improving Independent Innovation Capability. Independent innovation is the core

competitiveness of the state, and is the key of improving engineering quality and obtaining the

survival and development. If we construction high standards highway, experience of making great

efforts in innovation of high-speed rail must be learned. Innovation work should be well done in

technology, management, materials and product development, and all kinds of modern high-tech

innovation achievements should be used for highway construction.

High standard, strict requirement. Basic construction procedure must be strictly implemented,

perfect quality assurance and production safety guarantee system must be established. problems that

may occurs in the construction process foresee must be predicted and plans and guard processing

programs that to solve problems must be made in advance. The engineering cost must be reasonably

determined. Otherwise, we should choose construction companys and supervising units which have

high construction ability, strong quality consciousness, high credibility, rich experience, advanced

equipment , complete quality guarantee system. To ensure that all project completing on time and

quality guaranteed, materials select, construction and final acceptance must be achieved perfectly and

strictly in accordance with the national specifications and standards.

Do Waterproof Job. Water has a large influence on the highway, so waterproof job must be well

done in the process of design, construction and operation.

Conclusions

There are two kinds important reasons which lead to short life and inefficient of highway service. One

is that there are more vehicles driving fast and overload on highway, the other is low standards and

bad construction quality of highway. So, building high-standard, high-speed, large load, large flux

highway on the basis of improving mechanical properties and construction standards of highway is

imperative. Through the above analysis and measures research, after improving construction level and

quality standards of highway, cost of highway construction was increased, but immeasurable

economic benefits and social benefit could be got. Life of highway can be increased, maintenance and

management fees can be effectively reduced, national construction and people's increasing traffic

demand can be satisfied. So, improving construction standard of highway to prolong service life is a

great measure and correct choice to solve highway traffic problems at present.

For example, the original standard of Pushang road in Puyang city of Henan province, is low, this

highway be used less than five years after construction. When rebuilding, Construction standards is

improved(only grassroots become lower concrete), the road has serve for fifteen years, and is still in

Advanced Materials Research Vols. 243-249 4277

good condition. So, life of highway and benefit will be highly improved by improving the

construction standard.

References

[1] X.W. Song, H.Y. Zhang and X. Feng: Summary of Current Research on Rural Road. Journal of

Chongqing Jiaotong University, Vol. 24 (2005), p. 77-79(In Chinese).

[2] J.R. Xie: Countermeasures on Improving Management of County and Township Roads.

Management and Observer, Vol. 26 (2010), p. 222(In Chinese).

[3] X. Long, Q. X.. Zhang: Highway Engineering (Beijing Jiaotong University Press, Beijing

2008)(In Chinese).

[4] Z. Q. Jin, L. X. Xia: Highway Design (China Communications Press, Beijing 2002)(in chinese).

[5] J.C. Pan, Z.S. Qin: Discuss on Improving Construction Quality of Highway. West China

Development, Vol. 2 (2010), p. 77-78(In Chinese).

[6] S.J. Zhu: Research on Quality Control in Projects of Construction Units. Management and

Technology of SME, Vol. 15 (2010), p. 155(In Chinese).

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