共查询到20条相似文献,搜索用时 484 毫秒
1.
This study focuses on determining the effects of styrene–butadiene–styrene (SBS) and using mineral filler with lime on various properties of hot mix asphalt especially moisture damage resistance. The asphalt cement was modified with 2%, 4% and 6% SBS. The lime treated mixtures containing 2% lime by weight of the total aggregate as filler. The physical and mechanical properties of polymer modified binder and binder–aggregate mixes were evaluated through their fundamental engineering properties such as dynamic shear rheometer (DSR), rotational viscosimeter (RV) for binders, Marshall stability, stiffness modulus, indirect tensile strength and moisture susceptibility for mixes. The retained Marshall stability (RMS) and tensile strength ratio (TSR) values were calculated to determine the resistance of mixtures to moisture damage. To investigate clearly the effective of SBS and lime seven freeze–thaw cycle was applied to specimens at TSR test. The results indicate that application of SBS modified binders and lime as mineral filler one by one improves the stability, stiffness and strength characteristic of hot mix asphalt. According to retained Marshall stability it is concluded that addition of only 2% lime have approximately same effect with addition of 6% SBS. Using lime together within the SBS modified mixes exhibit high accordance and exacerbates the improvement of properties. Specimens containing both 2% lime and 6% SBS, have the highest stiffness modulus which is 2.3 times higher than those of the control mixture and showed the least reduction in tensile strength ratio while maintaining 0.70 tensile strength ratio after seven freeze–thaw cycle. 相似文献
2.
This paper presents a research to recycle the waste vinyl (waste polyethylene film: WPE film) in asphalt mixtures for improving the performance properties of the mixtures. Conventional Marshall mix designs were carried out with varying WPE contents, and the best performing content of WPE film was determined from the previous study. Also, asphalt mixtures with two commercial polymer modifiers, low-density polyethylene (LDPE) and a styrene–butadiene–styrene (SBS), were used to compare the effectiveness of WPE-modified mixture. The strength characteristics such as Marshall stability and indirect tensile strength (ITS) were evaluated, and the wheel tracking test, result of which is generally considered to reflect the field performance, was conducted to measure the rutting resistance of the asphalt mixtures. From the results of this study, asphalt mixture with waste vinyl showed much better rutting resistance than normal asphalt mixture without WPE. It is hypothesized if an optimum content of waste vinyl is used, it is expected that the waste vinyl will be effective as much as commercial modifier in improving the performance of asphalt pavements. 相似文献
3.
《Construction and Building Materials》2010,24(11):2091-2100
The rationale behind an asphalt mix design is optimizing the binder content for the desired aggregate gradation to satisfy the specified volumetric and strength requirements. The designed asphalt mix should be durable and cost effective. The mechanical behavior of a designed asphalt mix is affected by the traffic loading and climatic variations. To improve the mechanical properties of asphalt mixes, additives are added to the base asphalt binder. These binders are called modified asphalt binders. The objectives of the present study are to compare the performance of asphalt mixes with different binders by two different mix design methods and to optimize the asphalt binder type to achieve the desired performance. Two methods of mix design namely, Marshall and Superpave mix design methods are considered. The performances of asphalt mixes viz., tensile strength, moisture damage, densification and rutting resistance were compared. The results indicated a statistically significant difference in the optimum asphalt binder content from the two mix design methods. The Marshall method of asphalt mix design is found to yield lower optimal asphalt binder content when compared to the Superpave method of mix design. The moisture susceptibility and construction densification index of asphalt mixes designed using Superpave method were found to be significantly lower than that of the mixes designed by Marshall method. Optimization using a Mixed Integer Linear Program (MILP) indicated that the polymer modified asphalt binder outperforms the requirements of engineering properties when compared to other commercial binders used in the study. 相似文献
4.
5.
在USP温拌改性剂研究成果基础上,探讨了USP温拌改性沥青混合料的组成设计、路用性能和施工技术,结论表明:用马歇尔试验,可以确定最佳沥青用量,且具有良好的高温稳定性、水稳定性;施工技术控制重点是拌合均匀、保证压实。 相似文献
6.
为了研究混杂纤维大体积混凝土水化热处理配合比试验与力学特性,首先通过对现有纤维混凝土的情况进行分析,选择通过将不同模量的纤维进行混掺的方式,将聚丙烯腈纤维还有玄武岩纤维混掺,形成混杂纤维混凝土;然后进行配合比设计,根据研究目标即纤维对混凝土力学特性的影响,将研究内容分为纤维总掺量对混凝土力学特性的影响、纤维比值对混凝土力学特性的影响两部分;最后,按照混凝土配合比设计进行试验,分别研究纤维总掺量及纤维比值对混凝土抗折强度的影响、纤维总掺量及纤维比值对混凝土抗压强度的影响、纤维总掺量及纤维比值对混凝土抗拉强度的影响,得到最佳纤维总掺量以及玄武岩纤维和聚丙烯腈纤维混合的最佳比值,并且分析试验结果。对于抗折强度最佳纤维总掺量为0.1%、最佳纤维比值为1∶1;对于抗压强度最佳纤维总掺量为0.08%、最佳纤维比值为1∶1;对于抗拉强度最佳纤维总掺量为0.1%、最佳纤维比值为3∶1。 相似文献
7.
Kalia Anurag Feipeng Xiao Serji N. Amirkhanian 《Construction and Building Materials》2009,23(5):2035-2040
The vast quantity of waste materials (such as roofing polyester waste fibers) accumulating throughout the world is creating costly disposal problem. The use of these materials was proved to be economical, environmentally sound and effective in increasing the performance properties of the asphalt mixture in recent years. The primary objective of this research was to determine whether homogeneously dispersed roofing waste polyester fibers improve the indirect tensile strength (ITS) and moisture susceptibility properties of asphalt concrete mixtures containing various lengths and percentages of the fiber in various aggregate sources. The experimental design included the use of three aggregate sources, two lengths (0.635 cm (1/4 in.) and 1.270 cm (1/2 in.)) of this fiber, and two fiber contents (0.35% and 0.50% by weight of total mixture). The results of the experiments found that, in general, the addition of the polyester fiber was beneficial in improving the wet tensile strength and tensile strength ratio (TSR) of the modified mixture, increasing the toughness value in both dry and wet conditions, and increasing the void content, the asphalt content, the unit weight, and the Marshall stability. 相似文献
8.
9.
At all stages of pavement life, the highway surface should have some sort of roughness to facilitate friction between car wheels and pavement surface. Skid resistance is a measure of the resistance of pavement surface to sliding or skidding of the vehicle. It is a relationship between the vertical force and the horizontal force developed as a tire slides along the pavement surface. The texture of the pavement surface and its ability to resist the polishing effect of traffic is of prime importance in providing skidding resistance. Polishing of the aggregate is the reduction in microtexture, resulting in the smoothing and rounding of exposed aggregates. This process is caused by particle wear on a microscopic scale. It is a common fact that the lower the skid resistance value, the higher the percentage of the traffic accidents, especially during the wet seasons. Having a low skid resistance value at an asphalt concrete surface might be attributed to one or more of the following reasons: (1) use of higher asphalt content than recommended by the mix design procedure, (2) the Marshall mix design procedure itself, (3) used aggregate gradation, and (4) aggregate quality. To evaluate these factors, a comparative study was performed to find the British Pendulum Skid Resistance Number for a number of mixes. These mixes included, an asphalt concrete mix using local aggregate at the optimum Marshall asphalt content, mixes with 0.5% and 1.0% asphalt contents higher than Marshall optimum asphalt content, a mix designed using Superpave design procedure, a mix with steel slag to replace 30% of limestone aggregate, and a mix with stone matrix aggregate gradation. It was found that the mix with 30% slag has the highest skid number followed by Superpave, SMA, and Marshall mixes, respectively. It was also observed that increasing the asphalt content above the optimal asphalt content value decreases the skid resistance of these mixes. 相似文献
10.
Ali Ergün 《Construction and Building Materials》2011,25(2):806-812
Diatomite is a pozzolanic material containing amorphous silica, cristabolite and minor amounts of residual minerals. Waste marble powder (WMP) is an inert material which is obtained as an industrial by product during sawing, shaping, and polishing of marble and causes a serious environmental problem. This paper describes the procedures and results of a laboratory investigation of mechanical properties carried out on the concrete specimens containing diatomite and WMP as partial replacement of cement in concrete. The laboratory work essentially consists of characterization of the raw and waste materials, preparation of concrete specimens with diatomite and WPM in different ratios by weight as replacement for cement and a superplasticizing admixture to reduce water demand and compression and flexural tests of the specimens. Test results indicated that the concrete specimens containing 10% diatomite, 5% WPM and 5% WPM +10% diatomite replacement by weight for cement had the best compressive and flexural strength and the replacement of cement with diatomite and WMP separately and together using a superplasticizing admixture could be utilized to improve the mechanical properties of the conventional concrete mixtures. 相似文献
11.
对废旧轮胎橡胶粉碎料作为添加成分取代部分细骨料的混凝土的力学性能进行了试验,制备了多组不同橡胶粒径和掺量的橡胶粉改性混凝土试件,试验采用的橡胶粉为废旧轮胎橡胶胶粉,掺量为细骨料体积的5%、10%、15%和20%,探讨橡胶粉粒径和掺量变化对力学性能的影响,结果表明:掺人废旧轮胎橡胶胶粉的混凝土的抗压强度、抗折强度会随橡胶掺量的增加而降低;折压比增加。 相似文献
12.
13.
This paper investigates the viability of using starch (ST) as a new modifier for asphalt paving materials. Different ratios of ST (2.5, 5.0, and 7.5% by weight of asphalt) were blended with 70/100 paving grade asphalt. Unmodified and modified asphalt binders were subjected to physicochemical, alkali, acid and fuel resistance tests. The performance tests including, Marshall stability, Marshall Quotient (MQ), tensile strength, tensile strength ratio, flexural strength, rutting resistance and resilient modulus (MR) were carried out on unmodified and modified stone matrix asphalt (SMA) mixtures. The analyses of test results show that the performance of ST-modified asphalt mixtures are better than conventional and styrene–butadiene–styrene (SBS)-modified mixtures. The rutting potential, moisture susceptibility and temperature susceptibility can be reduced by the inclusion of ST in the asphalt mixture. The laboratory MR values are lower than the calculated ones using the empirical equations. The results also revealed that this modifier can be used as anti-stripping agent. It also shows resistance to fuels and most common chemicals. A ST content of 5% by weight of asphalt is recommended for the improvement of the performance of asphalt concrete mixtures similar to that investigated in this study. 相似文献
14.
15.
16.
Deniz Arslan Metin Gürü M. Kürşat Çubuk Meltem Çubuk 《Construction and Building Materials》2011,25(10):3863-3868
This study investigates the modification of bitumen with triethylene glycol based polyboron (TEGPB). TEGPB is a new additive material which was chemically synthesized at laboratory conditions. Four different TEGPB concentrations were used to modify 50/70 penetration grade bitumen: 1%(w/w), 2%(w/w), 3%(w/w) and 5%(w/w). The effects of TEGPB modification on the bitumen and bituminous mixture properties were determined by means of softening point, Marshall stability, Nicholson stripping, rotational viscosity (RV), Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR) tests. Amount of TEGPB to be used within the bitumen has been chosen as 2%(w/w) according to RV test results. BBR and Nicholson stripping test results have showed that creep properties and stripping resistance of the modified bitumen was not adversely affected. It was also found out that softening point and rutting resistance of the bitumen as well as Marshall stability of the bituminous mixtures were increased by TEGPB modification. 相似文献
17.
《Construction and Building Materials》2005,19(5):337-346
Like other construction materials, shingles have their own service life based on raw materials, production method and environmental and climatic conditions. At the end of their service life, shingles need to be replaced. However, these old shingles together with manufacturing scrap and handling waste require large storage areas and pollute the environment in time. Hence, additional usage of shingle waste is desirable. In this study, shingle waste in amounts of 1%, 2%, 3%, 4% and 5% by weight was added as an additive to asphalt concrete mixes prepared with the optimum binder content which yielded the best stability value was 5%. After determination of the optimum percentage of shingle to be added, rutting tests were performed on the specimens. Taking into account, the binder content existing in the shingle, mixtures were prepared with the reduced binder content by 0.5% and 1.0%. Test results show that waste shingles can be used in HMA as an additive to improve the Marshall stability and rutting resistance of the mixtures. 相似文献
18.
19.
为研究矿物掺合料与增效剂对混凝土力学性能的影响,设计了C30和C40两种强度等级的20个配合比及基准对照组配合比,每个强度等级又设计了3组单掺CTF混凝土增效剂时水泥用量分别减少7%、10%、15%的配合比,复掺时粉煤灰掺量分别为15%、20%、25%,硅灰掺量为6%和9%,CTF混凝土增效剂掺量为10%,通过测试试块在7d、28d、60d的抗压强度,研究其抗压强度随龄期的变化规律。结果表明,CTF混凝土增效剂单掺时水泥减少量为10%~15%的情况下,增效剂的增效效果最明显,且此时CTF混凝土增效剂对混凝土抗压强度也有很大的提高,当粉煤灰、硅灰以及CTF混凝土增效剂复掺时,试块抗压强度值高于基准组试块,此时粉煤灰最佳掺量为20%左右,硅灰掺量为6%左右,且复掺时由于增效剂的作用以及粉煤灰和硅灰的替代,节约了大量的水泥。 相似文献
20.
采用改进的全计算法对自密实混凝土进行配合比设计.在此基础上采用正交试验进一步研究了水泥、粉煤灰、砂、碎石和外加剂等因素对自密实混凝土工作性和强度的影响规律,优化和确定了自密实混凝土配合比。结果表明:改进的全计算法是一种科学、合理、准确的自密实混凝土配合比设计方法。 相似文献