Road Roller Research Articles

Problematics of Reliability of Road Rollers

Abstract This article refers to the reliability of road rollers used in a selected roadworks company. Information on the method of road rollers service and how the service affects the reliability of these rollers is presented. Attention was paid to the process of the implemented maintenance plan with regard to the machine's operational time. The reliability of road rollers was analyzed by determining and interpreting readiness coefficients.

TO THE QUESTION OF VIBRO-EXCITER’S ENERGY EFFICIENCY INCREASING FOR VIBRATING COMPACTORS IN THE SPHERE OF ROAD CONCTRUCTION

Introduction. The article considers the relevance of the subject of using vibratory compactors in the road construction field. Moreover, the shortcomings of existing unbalance exciters are revealed. In order to eliminate the drawbacks, we propose a new design of a crank-rod type vibration exciter. Therefore, the design is a new step in the development of directional oscillators, the use of which in road engineering would increase its productivity and efficiency. The main provisions, which allow to calculate energy efficiency and vibration parameters of a new exciter, are considered. The results of calculations and the dependence of the power exponent for the entire period of oscillatory motion are presented. The article proposes a new principle of designing periodic generators of directed force action. The scheme of the construction and its kinematic scheme are presented. The result of the research is to increase the energy efficiency of using vibrating compactors in road construction. Material and methods. A new design of a vibration exciter is presented, the dependence character of the direction of the driving force on time relative to the treated surface is revealed. Results. Increase energy efficiency of the building materials’ processing by vibrating road rollers are given. Discussion and conclusion. As can be seen, the proposed technical solution is a new step in the development of oscillators of directional action and their usage in road engineering, which would improve its productivity and efficiency of processing road building materials.

Justification of the road based seal model from the influence of road roller loads

Justification of the road based seal model from the influence of road roller loads

Modelling of a mecanum wheel taking into account the geometry of road rollers

During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of the road rollers, is their bearings. Depending on the load, carried by the vehicle and the rotational speed of the drive wheel, the bearings themselves can greatly affect the diameter of the rollers and the whole Mecanum wheels. The solution of this problem is presented in the paper. It is illustrated with virtual models elaborated in advanced program of the CAE class.

The Study of Performance in the Cement Stabilized Crushed Rock without Compression

The need of cement stabilized crushed rock was introduced in the situation that the road roller can’t vibrate in the rural areas through the construction of main road improvement. The gradation of cement stabilized crushed rock was proposed in the reference of all kinds of theoretical and empirical gradations. The optimization of some kinds of water-reducing additives was conducted by the way of normal consistency. Some experiments were conducted to determine how much the water-reducing additive can do in the compaction of cement stabilized crushed rock. At last, exam section was conducted to exam the results in the lab.

Theoretical research and analysis of work process of a road roller with local deformation of roll in compaction zone

Theoretical research and analysis of work process of a road roller with local deformation of roll in compaction zone

Design and Fabrication of a Road Roller with Double-Frequency Composed Vibration and Its Compaction Performance

To improve the efficiency of compaction and the compaction quality of pavement, a novel design principle of a roller based on double-frequency composed vibration (DFV) was put forward and adopted. According to the design function, the eccentric shaft parts of the steel wheel were designed and manufactured to match the vibration system and driving system, and a prototype of the DFV roller was obtained by assembling these modules. The frequency domain of the roller was simulated and tested. The consistent results showed that in a working state, the DFV roller could simultaneously excite two frequency components, thus providing an additional resonance frequency component in the compaction process compared with the case for the traditional vibratory roller with a single resonance frequency component. Moreover, the compaction experiment showed that the roller with two resonance frequency components provided better compaction strength and compaction depth than the traditional vibratory roller. In road construction, the DFV roller would be able to improve the efficiency of compaction and the compaction quality of the pavement, ultimately increasing pavement life.

The Research of Rod Roller Conceptual Design Based on the Innovation Theory of TRIZ

Abstract: Whereas there exist such problems as compaction blind spot in the edge and cornier area of construction rod, and the narrow site has disabled the large rod roller to go into operation, an innovative design method based on the TRIZ theory has been put forward. Meanwhile, a detailed solution to the conflicts generated in the efforts to improve the differency of the large road roller has been proposed through the use of the contradiction conflict solution matrix comprised by 39 engineering parameters and 40 pieces of inventive principles pertaining to TRIZ. Furthermore, the feasibility to conduct TRIZ-theory-based innovative design in the field of engineering machinery has been manifested, thus providing important theoretical tools for design ideas in the field of traditional engineering innovation.

The Design of Driver’s Seat Vibration System of the Road Roller Based on MATLAB

This project mainly studies the structure composition and the working principle of the seat vibration system of the roller . On this basis, dynamic equations are obtained according to the stress analysis of the simplified system of the seat vibration system of the roller, and then with the simulink module of MATLAB software, a simulation model is established as to the driver's seat system.Through the model simulation, the roller’s vibration of the the driver seat system is analysed,then based on the analysis, the optimization design can be done. Finally, through the research of this topic, the ride comfort of roller is been improved.

Study on Adhesion Property in the Process of Vibrating Compaction

In order to be convenient for engineering calculations, the relative experiment was designed after analyzing the reasons why the adhesion force on the front wheel of the single vibratory road roller changes in the process of vibratory compaction. According to the result of the experiment, a concept of effective adhesion coefficient is put forward and a calculation method of it is provided. Draw a conclusion that the utilization rate of adhesion coefficient is highest in two gear and hope that it has a positive effect on the parameter design of vibratory roller and engineering applications.

Antecedents of Health and Safety Issues Relating to Plant Trailer Wheels

Wheel detachment from plant trailers used on public highways represents a significant health and safety hazard and major financial risk, especially for construction and utility companies that rely on these type of trailers to transport machinery such as miniexcavators or road rollers. This study uncovers the antecedents of plant trailer wheel detachment and suggests pragmatic guidance for mitigating this risk. A case study using elements of action research studies the problem in the field through direct observation and stakeholder interviews. Analysis of resulting qualitative data conceptualizes antecedents on which guidance is formulated. Risks are found to result from a combination of physical failure underpinned by inadequate human interventions and poor risk management. The primary contributions of the study are that it describes entirely novel research on trailer wheel detachment, produces new safety guidance for businesses and practitioners that operate plant trailers, and resultantly contributes to lowering the risks identified.

Research on Cement Concrete Bridge Asphalt Pavement Compaction Technology

Based on influence of bridge structure caused by vibrating compaction and the properties of road roller, the combination of vibrating compaction and rubber-tyred kneading rolling can ensure the construction quality of cement concrete bridge deck asphalt mixture surfacing. It can guarantee the smoothness of asphalt mixture surfacing and avoid the shortage of compaction.

Evaluation of the Mechanical Properties of Field- and Laboratory-Compacted Hot-Mix Asphalt

The aim of this study is to investigate the effects of field-compaction conditions on the mechanical properties of asphalt concrete and then compare the properties with those of the specimens prepared with different Marshall hammer–blow numbers and gyratory-compactor gyrations. For this purpose, a binder layer was constructed with different compaction levels at different temperatures over a preconstructed plant-mix base layer. The B 70/100 bitumen and dense-graded limestone aggregate with a maximum size of 25.4 mm were used. The binder layer was divided into 12 sections, which were constructed with four different road roller–pass numbers and three different temperatures. The laboratory compaction conditions simulating all of the field compactions were assessed in indirect tensile strength, indirect tensile stiffness modulus, indirect tensile repeated load, and dynamic-creep tests. It was concluded that the field and laboratory specimens were affected by the compaction level and temperature in different ways. Furthermore, the specimens exhibited different performances even with the same air-void contents. The laboratory specimens with the same air-void contents as those of field specimens displayed much better performance than the field specimens.

Dynamic and Control of Vibratory Road Roller Based on Magneto-Rheological Semi-Active Damper

Comfort of the vibratory road roller is an important research title. A 2-DOF non-line model is set up, which is more close to the actual situation of the vibratory road roller. A simulation using MATLAB/SIMULINK is carried out to validate this model and study its dynamic characteristic and analyze the motion laws of its housing and wheel. A kind of Magneto-rheological (MR) damper is designed which has been widely used in automotive and bridge damping in recent years, and applied to a vibratory road roller to control it. The control strategy uses fuzzy control. The results indicate that the damping performance of the vibratory road roller which applied MR damper is improved remarkably.

Study on Impact Compaction of Aeolian Sand Subgrade and its Effect Evaluation

In order to solve the problem of aeolian sand subgrade compaction, we studied the technology of impact compaction, applied it to the engineering practice and analyzed its effect with Rayleigh wave. The technology of impact compaction can combine the compaction of potential energy and kinetic energy and make it easier for the materials to reach their elastic stage. With the combined function of "knead-roll-impact", the impact compaction road roller can compact the soil body and offer 6～10 times impact force and 3～4 times the depth of influence more than the vibratory roller. The impact compaction methods of aeolian sand subgrade were put forward. The comparative field compaction tests between impact and vibratory compaction are carried through, which are detected by Rayleigh wave. The results show that the impact compaction can make the density of the aeolian sand subgrade 2～5% higher than the vibratory compaction, and reach the influence depth of 7 metres. To sum up, the impact compaction can clearly increases the strength and stiffness of aeolian sand subgrade with a dynamic elastic modulus of 202.63MPa.

THE STATUS QUO AND DEVELOPMENT TENDENCY OF CONSTRUCTION MACHINERY AND ITS HYDRAULIC COMPONENTS IN CHINA

The status and development tendency of construction machinery in china in recent years will be introduced; especially the outputs and performance level of the main products such as excavator, loader, crawler crane, truck crane, road roller and rotary drilling rig. Then the application of new products from internal corporation is analyzed and the research and development tendency of homemade hydraulic components of construction machinery field are also included. This paper introduces not only the national product standards of construction machinery but also the national policies and regulations for energy saving and pollution reduction in China.

Effects of a roller and a tracked vehicle on the compaction of a high lifted decomposed granite sandy soil

The aim of this research was to innovate a new compaction machinery by comparing experimentally the effects of a two-axle, two wheel road roller and a tracked vehicle on the compaction of a decomposed granite sandy soil with a high spreading lift. By measuring the amount of sinkage of the terrain surface, the dry density distribution versus depth using a cone penetrometer, the normal earth pressure distribution versus depth using a stress state transducer (SST), the effects of the road roller and the tracked vehicle on the increment of the soil dry density were considered theoretically. It was observed that the tracked vehicle showed a larger amount of sinkage and a larger dry density distribution versus depth than the roller. The ratio of shear stress to normal stress was still large enough at the deep stratum, so that an optimal shear strain was developed on the whole range of the high lifted stratum and it increased the soil compaction density due to the dilatancy effect.

Researches on Determinig the Optimum Watering Requirement and The Resistance to Treading Effect of Lippia Grass Phyla nodiflora (L.) Greene Under the Growing Conditions of İzmir

This research, based upon determining the growth rate of lippia grass Phyla nodiflora (L.) Greene, considering the varied degrees of the watering and the treading factors upon which in the conditions of Izmir, has been carried out in Landscape Architecture Department, Faculty of Agriculture, Ege University. The trial has been set upon the randomized blocks in trial design with the 3 repetition, as follows; Watering factor; S_1 : No watering. S_2 : Once a week (10 lt/m^2). S_3 : Twice a week (10 lt/m^2), with the 84 hour interval. Treading factor; B_1 : No rolling. B_2 : Twice a week, rolling with the 40 kg' road roller - twice treading, with the 84 hour interval. B_3 : Twice a week, rolling with the 40 kg' road roller - four times treading, with the 84 hour interval. The results research show that, the effect of the watering and the treading factors upon the growth of lippia grass is statistically remarkable.

OPTIMUM TRAFFICABILITY CONTROL SYSTEM OF A TWO-AXLE, TWO-WHEEL ROAD ROLLER DURING DRIVING AND BRAKING ACTION

OPTIMUM TRAFFICABILITY CONTROL SYSTEM OF A TWO-AXLE, TWO-WHEEL ROAD ROLLER DURING DRIVING AND BRAKING ACTION

Subsoil compaction to improve water use efficiency and yields of rainfed lowland rice in coarse-textured soils

Field experiments during the 1992 and 1993 wet seasons examined in situ water conservation in rainfed lowland rice ( Oryza sativa L.) grown on a loamy sand by comparing subsoil compaction (C) with puddling (PUD), a plastic sheet barrier at 40 cm depth (PLS), and dry tillage (DT). Soil was compacted with six (C6) or nine (C9) passes of a 12-ton road roller over the soil surface with (+V) or without (- V) roller vibration. After compaction, soil was tilled to 20 cm depth. All plots except DT were puddled manually to 15 cm depth. Rice seedlings (Cultivar KDML105) were transplanted in all plots. Degree and depth of compaction increased with number of passes and with vibration of the roller. Treatment C9 + V compacted soil to at least 60 cm depth. Percolation decreased from 11.8 mm d −1 in DT and 6.3 mm d −1 in PUD plots to 1.4 mm d −1 in C9 + V plots. Compaction increased total days with surface water accumulation from 44 days in DT and 68 days in PUD plots to 90 days in C9 + V. Rice in plots with subsoil compaction had nearly twice the root length and root mass densities in the 0–20 cm soil layer and significantly increased shoot growth as compared with rice in DT and PUD plots. As compared with PUD, the standard tillage practice of farmers, treatment C9 + V increased grain yield by 1.48 Mg ha −1 (59%) in 1992 and by 0.98 Mg ha −1 (88%) in 1993, with 1.6 times greater water use efficiency (WUE) in 1992 and 1.9 times greater WUE in 1993. Treatment PLS yielded more grain than PUD, but less than C9 + V. We conclude that subsoil compaction technology is applicable at a field scale for rainfed rice grown in coarse-textured soils.