Amount Of Crumb Rubber Research Articles

Seismic Performance of Infilled Reinforced Concrete Frame with Crumb Rubber Mortar Wall Panel

In this paper, the seismic performance of reinforced concrete (RC) frames with crumb rubber mortar wall panels is reported. The tests of the crumb rubber mortar were conducted to obtain model parameters for equivalent diagonal compression struts. With a higher percentage of sand replacement by crumb rubber, the unit weight, the compressive strength, the tensile strength, and the modulus of elasticity of the crumb rubber cement mortar are decreased. Nonlinear pushover analysis of a simple frame shows that the RC frame with a wall panel with less crumb rubber demonstrates lower lateral deformation ability. The failure modes are affected by the amount of crumb rubber and are dependent on the modeling choice of the equivalent compression strut as the wall panel representative. Finally, the seismic performance of the RC building was studied by the equivalent static approach to explore the influence of the crumb rubber mortar wall panels on internal forces and deformations of the frame. With a higher percentage of crumb rubber, the weight of the infill wall panels and the overall weight of the building are reduced, which meets lower seismic base shear demand. This benefit is, however, traded off with higher lateral deformation and also higher inter-story drift of the studied building frames. Doi: 10.28991/CEJ-2024-010-02-09 Full Text: PDF

Designand Properties of Crumb Rubber Aggregates Additive in Hot Mixture Asphalt Concrete

Abstract: This research aims to establish the design and properties of crumb rubber aggregates additive in hot mixture asphalt concrete. Rubber crumb is rubber waste which is processed through mechanical grinding or tire milling into small splinters. The objective of this research is to have high durability of flexible pavement with different percentages of crumb rubber. The experiment was done respectively through several phases as follows: preparation, quality examination of materials such as aggregate and asphalt, mixed-planning, and specimen testing implementation with Marshall Test. Properties of crumb rubberlike type stability and flow of durability can affect the different stability and flexibility of pavement. The data collected from the laboratory experiments were presented in different forms like tables, charts, diagrams, etc. The results from the crumb rubber asphalt mixture show that there is an increase in the amount of crumb rubber in a mixture of hot mix concrete asphalt. This mixture can increase the Marshall stability by 2.5 % crumb rubber higher than the other mixtures with crumb rubber.

Experimental Study of the Effect of Crumb Rubber on Properties of Asphalt Mix by Wet Process

The increase in the number of vehicles during the past twenty years has dramatically increased the traffic density and axial loading. In addition to the construction failures and lack of periodic maintenance, rapid deterioration of the road condition happens. So, it was necessary to find solutions to these problems that have been growing for years. One of these solutions is to improve the asphalt mixture to resist excessive loads and weather fluctuations. This research aims to investigate the addition of crumb rubber derived from recycled tires; to the asphalt mixture for improving performance characteristics and to compare the improved and unimproved samples. It is worth mentioning that crumb rubber addition to the asphalt mixture is considered one of the smart solutions for sustainability that the world is heading towards today, considering that the crumb rubber comes from waste tires, which is difficult to eliminate and pollute the environment. Four different proportions of crumb rubber have been added in this research (6, 9, 12, and 15%); by weight of bitumen to (60-70) asphalt binder, with a particle size passing from sieve no.50 (0.3 mm). The aggregate gradation is designed according to the Marshall method with a (12.5 mm NMAS) wearing course to obtain the optimum asphalt content and to prepare laboratory samples to perform various laboratory tests. Marshall Stability and flow, indirect tensile strength (ITS), moisture susceptibility, and permanent deformation of asphaltic mixes with different contents of crumb rubber were investigated. The results of the tested samples were compared with the original samples. It is shown that the asphaltic mixes performance has been improved when adding a certain amount of crumb rubber. Marshall Stability is increased by 29.2% when adding 9% CR by the weight of bitumen. However, the addition of crumb rubber can increase the stiffness of the asphalt mixture resulting in a more rigid pavement structure that is less prone to moisture damage and rutting under traffic load.

Rheological properties and microscopic mechanism of waste cooking oil activated waste crumb rubber modified asphalt

In this paper, the surface activated crumb rubber with waste cooking oil (WCO) was studied to improve the performance of crumb rubber modified asphalt. The activated waste crumb rubber modified asphalt (OCRMA) with different amount of crumb rubber was prepared to study the microscopic appearance of OCRMA by scanning electron microscope and fluorescence microscope and analyze the surface performance. The rheological properties and microscopic mechanism of OCRMA were characterized by dynamic shear rheological test, multiple stress creep recovery (MSCR) test, BBR test and infrared spectroscopy. The results show that the dissolution degree of waste crumb rubber is improved after WCO activation, and the compatibility with asphalt components is enhanced, and the stable cross-linking structure is formed, which improves the asphalt performance. The several new absorption peaks, which were obvious, were all caused by the composition of WCO, that is, there was no significant chemical change during the interaction between the activated crumb rubber and base asphalt. Compared with the common waste crumb rubber modified asphalt (CRMA), activation with WCO can significantly reduce the viscosity of CRMA, decrease the difference of segregation softening point by 27%, and enhance the low temperature performance by 30%. The aging degree is greatly reduced, and the anti-aging performance of OCRMA is increased by about 20% with the same dosage. The high temperature performance, though higher than that of base asphalt, decreases to some extent. After comprehensive analysis, the optimal dosage of crumb rubber for OCRMA is 30%.

Chemical attack on concrete containing a high volume of crumb rubber as a partial replacement for fine aggregate in engineered cementitious composite (ECC)

Today, scrap tire is disposed of by open burning which harms the environment. To reduce the wastage of the resource, a sustainable approach is needed to dispose of the waste tire as a partial replacement of the fine aggregate in concrete mixes. This research has been conducted with a focus on the chemical attack of an engineered cementitious composite (ECC) containing a high volume of crumb rubber in terms of durability, behaviour, and comparison with conventional concrete. Two variables have been considered in developing rubberized ECC mixtures, that is, the amount of crumb rubber as a replacement for fine aggregate by volume of 0%–30% and PVA fibres by volume of 0%–2% to cementitious materials. The resistance properties of ECC incorporating crumb rubber were investigated for 13 different variable combinations developed using response surface methodology (RSM). The experimental results revealed that the presence of crumb rubber in the ECC matrix enhanced the resistance of the ECC in both acidic and sulphate environments. It was also revealed that by incorporating 15% crumb rubber, the loss of compressive strength significantly reduced from 38% to 15%.

Pavement and Noise Reduction Performance of Open‐Graded Asphalt Friction Course Improved by Waste Tire Crumb Rubber

To further reveal the road performance and noise reduction performance of open‐graded friction course (OGFC), the crumb rubber prepared by adding waste tires were considered, and the performance requirements of the material were put forward. To avoid the influence of rubber particle swelling on aggregate, the special gradation and mix proportion of OGFC mixture were designed, and the particle size of 4.75 mm was proposed as the control size. The test results show that the aggregate forms a good embedded structure. The resilient modulus, deformation performance, and fatigue performance of R‐OGFC asphalt mixture with different crumb rubber contents were studied. According to the test results, the rubber particle content under the best road performance and noise reduction effect was proposed. The results show that, after adding a certain amount of crumb rubber, the performance of asphalt mixture has been greatly improved, especially the dynamic stability has been improved by 84%. Although the resilient modulus has decreased by 10%, the creep performance has decreased by 37%, and the fatigue life has decreased by 31% (2% rubber content), the noise reduction can reach 3.6–8.6 dB, and the noise reduction performance is significant. This shows that the best content of rubber particles is between 1.5% and 2%, and the R‐OGFC mixture modified by rubber has a good application prospect.

Poroelastic Material for Urban Roads Wearing Courses

Conventional road materials used for producing wearing courses of roads are based on mineral aggregate and bituminous or Portland cement binders. The road materials must be optimized for different properties, including skid resistance, durability, rolling resistance and tire/road noise. Unfortunately, it seems that within classic technologies it is very difficult to achieve further reduction of tire/road noise. Innovative porous material PERS that contains considerable amount of crumb rubber seems to have great potential of traffic noise reduction. The paper presents brief history of PERS development, its present stage and unexpected properties, for example, spill fuel fires retardation.

Investigation of Low-Temperature Behavior of Stone Mastic Asphalt Mixtures Modified with Paraffin and Crumb Rubber

In hot mix asphalts at low temperatures, cracks occur due to thermal tension and these cracks cause water to leak inside the pavement and the pavement gets deformed sooner than expected. In order to improve the properties of bituminous mixtures, mostly polymer type additives are used in the modification of the bitumen. These types of improvements usually have positive effects on the high-temperature behavior of the mixture. In this study, semi-circular bending test, which is the most commonly used method in the literature to investigate the low-temperature behavior of bituminous mixtures, was performed. In the study, the resistance of stone mastic asphalt mixtures, which were prepared with modified bitumen with a constant 3% of paraffin and various amounts of crumb rubber, to crack formation and its movement was identified. As a result, it was concluded that the effects of additives on crack formation and its movement is varied and the relation between the fractured aggregate surface areas and the fracture toughness of the mixture can be determined by the image processing method.

Effect of Modified Rubber Particles Mixing Amount on Properties of Cement Mortar

The crumb rubber cement mortar is prepared by the crumb rubber aggregates in 60 mesh which are modified by 1% polyvinyl alcohol (PVA) solution. Some mechanical properties of cement mortar with different crumb rubber aggregate amounts are researched including compressive strength, flexural strength, the ratio of compressive strength to flexural strength, impact resistance, and dry contraction percentage. In our tests, we consider six kinds of the rubber contents, 0%, 7.5%, 15%, 19%, 22.5%, and 30%, respectively. The optimal mixing amount of crumb rubber is determined by measuring three indices, the ratio of compressive strength to flexural strength, impact resistance, and dry contraction percentage. It is shown by test that the ratio of compressive strength to flexural strength is the smallest when the mixing amount of rubber is 19%; meanwhile high impact resistance and rational drying shrinkage are observed. The optimal mixing amount of the rubber particles is 19% determined by this test.

A quiet poroelastic road surface manufactured in a normal asphalt mixing plant

A poroelastic road surface for low tire/road noise has been developed. It is manufactured using conventional asphalt mixing plants and conventional paving machines. Crumb rubber was added to the mix for attaining the desired elastic characteristics. The crumb rubber was subject to a long term pre-treatment before feeding it to the plant mixer. This ensures both long term durability and excellent adhesion to the binder. The crumb rubber grain size and amount in the mix has been carefully tuned to the aggregate grain size. By the pre-treatment of the crumb rubber the crumb rubber amount can be freely selected since it is not locked to the amount of binder (as for the hot bitumen pre-mixer technique) Single layer poroelastic road surface sections has been paved in Gothenburg. The reduction of noise relative to a SMA16 was found to be 4-6 dB(A) depending on the vehicle speed and amount of crumb rubber. The surface is almost unaffected by wear after 6 months winter traffic with studded tyres. Tuning the recipe for further increased reduction of the tire/road noise continues. Fundings from European Commission (project Quiet City Transport (QCITY)) is acknowledged.

Physico-mechanical and thermal performances of newly developed rubber-added bricks

The new European energy regulation now considers a high standard of thermal protection in buildings with reasonable energy consumption, satisfactory thermal comfort conditions and low operational costs. A series of significant restrictions on the disposal of used tires in landfills, stockpiles, or illegal dumping grounds are also imposed in recent European Union directives. The potential use of crumb rubber–concrete combination, in favor of these arrangements, for producing a low cost and lightweight composite brick with improved thermal resistance is examined here. The physico-mechanical and thermal insulation performances of these rubber-added bricks are investigated. The obtained compressive strength, flexural strength, splitting strength, freezing–thawing resistance, unit weight and water absorption values satisfy with the relevant international standards. The experimental observations reveal that high level replacement of crumb rubber with conventional sand aggregate does not exhibit a sudden brittle fracture even beyond the failure loads, indicates high energy absorption capacity, reduces the unit weight dramatically and introduces smoother surface compared to the current concrete bricks in the market. Thermal insulation performance is improved by introducing various amount of crumb rubber into the ordinary cementitious mixes. The percentage-wise improvements in thermal insulation performance have varied nearly between 5 and 11%, depending on the amount of crumb rubber used.

Characteristics of crumb rubber modified (CRM) asphalt concrete

The mix design for CRM asphalt concrete with the Marshall method and laboratory tests to evaluate low temperature behaviors and temperature susceptibilities of CRM asphalt concrete are presented. The mix design was performed using one asphalt cement (120/150 penetration grade), five aggregate gradations for three rubber contents (0, 3, and 5% by weight of aggregate) and both pretreated and untreated crumb rubber (passenger tire). All mixtures satisfied the Marshall mix design criteria. For laboratory tests, two asphalt cements (85/100 and 120/150 penetration grade), three aggregate gradations for three rubber contents (0, 3, and 5% by weight of aggregate) and two types of pretreated crumb rubber (passenger and industrial tires) were used. The addition of crumb rubber did not significantly affect the overall temperature susceptibility of the mixtures. It did, however, substantially decrease the mixture modulus at any given temperature. The decrease in modulus was accentuated as the content of crumb rubber increased. The potential for thermal cracking decreased with the amount of crumb rubber. This demonstrated that a CRM asphalt mixture could relieve stress build up by its ability to strain.