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Concrete with Coconut Fibre Treated with Sodium Hypochlorite – Compressive and Flexural Strength 次氯酸钠处理椰子纤维混凝土的抗压和抗弯强度
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22058
N. Ibrahim
Concrete needs to be reinforced to improve its engineering qualities. Coconut fibres were employed for this study since they are widely accessible and come in big numbers. The study compares the qualities of plain concrete and concrete reinforced with coconut fibre based on a laboratory experiment. Better management of these waste fibres will result from using coconut fibres. Two types of coconut fibre treatment were employed – treatment with tap water and treatment with sodium hypochlorite. It is found in this study that adding 1% of coconut fibre does not increase the concrete strength after 7 and 14 days of curing. However, it was discovered that using 1% coconut fibres treated using tap water increased the compressive and flexural strength of the concrete after 28 days of curing by roughly 4% and 3%, respectively. Compressive and flexural strength development agrees very well with each other. Hence, it is concluded that 1% was the ideal fibre concentration (by weight of cement) to obtain a better 28th day of compressive and flexural strength, although not for 7 and 14 days. However, concrete with the highest strengths demonstrated a very low slump value, only 20 mm. A smaller or bigger slump value showed smaller concrete strengths.
混凝土需要进行加固,以提高其工程质量。椰子纤维被用于这项研究,因为它们很容易获得,而且数量很多。在室内试验的基础上,对普通混凝土和椰子纤维增强混凝土的性能进行了比较。使用椰子纤维可以更好地管理这些废弃纤维。采用自来水处理和次氯酸钠处理两种方法处理椰子纤维。本研究发现,在养护7d和14d后,加入1%的椰子纤维对混凝土强度没有提高作用。然而,研究发现,使用自来水处理过的1%椰子纤维,在养护28天后,混凝土的抗压强度和抗弯强度分别增加了大约4%和3%。抗压强度和抗弯强度的发展规律吻合得很好。因此,可以得出结论,1%的纤维浓度(按水泥重量计)可以获得较好的28天抗压和抗弯强度,尽管7天和14天不是这样。然而,最高强度混凝土的坍落度值非常低,仅为20 mm。坍落度值越小或越大,混凝土强度越小。
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引用次数: 1
Seismic Behaviour of Beris Dam Under Six Earthquake Excitations by using Finite Element Method 贝里斯大坝在六次地震作用下的抗震性能有限元分析
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22051
R. Ismail
This paper focused on the behavior of the dam when exposed to seismic loading and ability of the dam to withstand the applied loads from various seismic events. The chosen concrete dam to be referred to in the two- dimensional analysis is Beris Dam located in Kedah, Malaysia. A nonlinear dynamic analysis is chosen to analyse the behavior of Beris Dam under selected ground motion. Analysis of the dam is performed using the finite element method by utilizing ABAQUS software. From the cracking analysis pattern, a crack appeared at the upstream face of the dam caused mainly by the excessive tensile stress. Based on the results, the displacement of the dam is increased with the increasing of ground motion data where the displacement occurred in the horizontal direction. The maximum stresses exerted by the dam structure do not exceed the allowable capacity of concrete dams. The stress behaviour of the dam was satisfactorily acceptable as the maximum normal stress and shear stress of the dam when numerous seismic loadings are applied do not exceed the allowable stress capacity which is 800 kN/m2.
本文重点研究了大坝在地震荷载作用下的性能,以及大坝承受各种地震事件荷载的能力。在二维分析中选取的混凝土坝是位于马来西亚吉打州的Beris大坝。采用非线性动力分析方法分析了Beris坝在选定地震动作用下的受力特性。利用ABAQUS软件对坝体进行有限元分析。从裂缝分析模式看,坝体上游面出现裂缝,主要是由于拉应力过大造成的。结果表明,在水平方向发生位移的地方,坝体位移随地震动数据的增加而增大。坝体结构施加的最大应力不超过混凝土坝的允许承载力。在多次地震荷载作用下,大坝的最大法向应力和剪应力不超过800千牛/平方米的许用应力能力,大坝的应力行为令人满意。
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引用次数: 0
Investigation on Surface Roughness and MRR in WEDM of Titanium Grade 7 (Ti-0.15Pd) Alloy using Statistical Techniques 基于统计技术的7级钛(Ti-0.15Pd)合金电火花线切割表面粗糙度及MRR研究
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22055
R. Suresh
Wire Electric Discharge Machining (WEDM) of Titanium grade alloys with coated electrodes has several advantages over the traditional machining process such as increased productivity, reduction of processing cost, and improved material properties. The main objective is to create a relationship between WEDM parameters such as Pulse-on (TON), Pulse-off (TOFF), and Indicated Power (IP) with surface roughness (Ra) and Material Removal Rate (MRR). In the present work, the performance of zinc-coated brass electrodes for WEDM of Titanium Grade-7 alloy was assessed and optimized with statistical technique. ANOVA analysis is used to analysis of the MRR and Ra and validated with regression. The ANOVA analysis results indicated that TON is the highest statistically significant and followed by TOFF and IP on MRR and surface roughness. The optimum combination of higher IP(6 A) and TON time(60 μs) and lower TOFF time (12 μs) is lucrative for a higher MRR of 8.5682 mm3/min and lower surface roughness of 1.66 μm. The SEM images showed homogeneous solidification, columnar grain structure, recast layer surface, and minor surface crack density were noticed at higher cutting conditions. The predicted model and confirmation test results were close to each other with minimum error (<5%), so the model is adequate.
与传统的加工工艺相比,采用涂覆电极对钛合金进行线切割加工具有提高生产率、降低加工成本和改善材料性能等优点。主要目标是建立电火花切割参数(如脉冲接通(TON)、脉冲关闭(TOFF)和指示功率(IP)与表面粗糙度(Ra)和材料去除率(MRR)之间的关系。本文采用统计方法对7级钛合金电火花线切割用镀锌黄铜电极的性能进行了评价和优化。采用方差分析对MRR和Ra进行分析,并用回归进行验证。方差分析结果表明,TON对MRR和表面粗糙度的影响最大,其次是TOFF和IP。高IP(6 A)、高TON时间(60 μs)和低TOFF时间(12 μs)的最佳组合可获得8.5682 mm3/min的高MRR和1.66 μm的低表面粗糙度。高切削条件下,合金凝固均匀,晶粒呈柱状组织,表面有重铸层,表面裂纹密度较小。预测模型与确认试验结果接近,误差最小(<5%),模型是合适的。
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引用次数: 0
Stress Shielding Prediction of Unicortical and Bicortical Screws: A Finite Element Analysis 单皮质和双皮质螺钉的应力屏蔽预测:有限元分析
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22052
K. Basaruddin
The stability in an implant fixation plays a vital role in ensuring proper formation and remodelling process of the fractured bone. Failure in implant fixation is commonly associated with short- and long-term instability of the bone-implant interface. The bone-implant interaction creates a complicated mechanical interplay that might influence the stress distribution and hence the biomechanical performance stability of the implant fixation. Furthermore, implant screw parameters namely thread size, geometrical design and material properties become additional factors that affect the bone-implant interaction. The purpose of this study was to investigate the effect of unicortical and bicortical screws’ parameters on the screw-bone interaction mechanism. To evaluate the stress transfers between screw and bone, the stress parameters namely stress transfer parameters (STP) was employed. A two-dimensional (2D) finite element model of full treaded screw was simulated while varying the parameters of the screw: two types of material (stainless steel A316 and titanium alloy Ti-6Al-4V), screw length and screw pitch. It was found that the lower in elastic modulus results to the higher stress transfer between implant- bone interface. As the titanium have lower elastic modulus, it gave higher values of STP which help to transmit and distribute stress better compared to the stainless steel. While the effect of varying screw pitch between two types of screws shows that STPs values of fully threaded bicortical screws shows significant result for finer pitch size that may advancing bone remodelling process at the early stage.
内固定的稳定性对于确保骨折骨的正常形成和重建过程起着至关重要的作用。假体固定失败通常与骨-假体界面的短期和长期不稳定有关。骨-种植体相互作用产生复杂的机械相互作用,可能影响应力分布,从而影响种植体固定物的生物力学性能稳定性。此外,种植体螺钉参数即螺纹尺寸、几何设计和材料特性成为影响骨-种植体相互作用的附加因素。本研究的目的是探讨单皮质和双皮质螺钉参数对螺钉-骨相互作用机制的影响。为了评估螺钉与骨之间的应力传递,采用应力参数即应力传递参数(STP)。在改变两种材料(不锈钢A316和钛合金Ti-6Al-4V)、螺杆长度和螺杆节距的情况下,建立了全履带螺杆的二维有限元模型。弹性模量越小,种植体-骨界面间的应力传递越大。由于钛具有较低的弹性模量,因此与不锈钢相比,钛具有较高的STP值,有利于应力的传递和分布。而两种类型的螺钉之间不同螺距的影响表明,全螺纹双皮质螺钉的STPs值在更细的螺距尺寸上显示出显著的结果,可能在早期促进骨重建过程。
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引用次数: 0
Corrosion Resistance Enhancement for Low Carbon Steel by Gas Phase Coating 气相涂层增强低碳钢的耐蚀性
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22059
Sameer K. Fayyadh
Corrosion Resistance Enhancement for low carbon steel is very important to extend its life service, the coating process is one of the methods which can using to achieve this, and it's the most important in surface treatments to improve the properties of metals and alloys surfaces such as corrosion resistance. In this work, low carbon steel was nitrided and coated with nano zinc using gas phase coating technical, to enhance the resistance of corrosion. The process included adding two layers. The first, a nitride layer, was added by precipitating nitrogen (N) gas, and the second, a zinc (Zn) layer, was added by precipitating Zn. The process of precipitating was carried out at different periods (5, 10, and 15 minutes). Scan electron microstructure (SEM), X-ray diffraction (XRD) and corrosion tests were carried out. The SEM and XRD results showed a new microstructure with the emergence of new phases (C3N4, Zn(N3)2, and γN). Also, the results of the corrosion test showed a significant improvement in corrosion resistance through a reduction in the corrosion rate (CR) and corrosion current density (icorr) which reached (1.598x10-3 mmpy) and (1.422x10-7 Amp/cm2) respectively, for coated samples, compared with 1.803×10-1 and 1.604x10-5, respectively, for the base metal. also found an appreciable increase in corrosion protection efficiency (CPE), which reached 99.11%.
提高低碳钢的耐蚀性对延长低碳钢的使用寿命非常重要,而涂层工艺是实现这一目标的方法之一,也是提高金属和合金表面耐蚀性等性能的表面处理中最重要的方法。采用气相涂层技术对低碳钢进行氮化和纳米锌涂层,以提高其抗腐蚀性能。这个过程包括添加两层。第一层是通过沉淀氮气添加氮化物层,第二层是通过沉淀Zn添加锌层。在不同时间(5分钟、10分钟和15分钟)进行沉淀过程。进行了扫描电子显微结构(SEM)、x射线衍射(XRD)和腐蚀试验。SEM和XRD结果表明,随着C3N4、Zn(N3)2、γN等新相的出现,复合材料的微观结构发生了变化。此外,腐蚀试验结果表明,通过降低腐蚀速率(CR)和腐蚀电流密度(icorr),涂层样品的耐蚀性显著提高,腐蚀速率(CR)和腐蚀电流密度(icorr)分别达到(1.598x10-3 mmpy)和(1.422x10-7 Amp/cm2),而母材的腐蚀速率和腐蚀电流密度分别为1.803×10-1和1.604x10-5。腐蚀防护效率(CPE)也有明显提高,达到99.11%。
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引用次数: 0
Effect of Rice-Husk as Replacement Cement on Mechanical Properties Concrete 稻壳替代水泥对混凝土力学性能的影响
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22056
Sakhiah Abdul Kudus
The cost of producing concrete has increased, and its effects on the natural environment have become apparent. The ideal solution is to use agro-waste material instead of cement in concrete. This research aims to determine how well RHA works as a cement substitute. At increments of 5%, 10%, and 15%, rice husk was applied in substitute of cement. Compressive and flexural tests were performed on a 100 mm x 100 mm x 100 mm cube and 100 mm x 100 mm x 500 mm prisms with varying percentages of RHA substitution. Findings show that the highest control sample has a compressive strength of 49.83 MPa while t The compressive strength began to drop at 5% RHA substitution. The compressive strength decreased as the percentage of RHA used increased from 10% to 15%. The flexural strength data shows that the 10% RHA has a maximum of 4.90 MPa. The lowest value is 3.85 MPa, and it is only seen from 5% of RHA. Thus, it can be inferred that an RHA replacement level of 5% in cement yields a tremendous increase in compressive strength.
生产混凝土的成本增加了,它对自然环境的影响也变得明显。理想的解决方案是用农业废料代替混凝土中的水泥。本研究旨在确定RHA作为水泥替代品的效果。以5%、10%和15%的添加量,用稻壳代替水泥。在100 mm × 100 mm × 100 mm立方体和100 mm × 100 mm × 500 mm棱镜上进行压缩和弯曲试验,并使用不同比例的RHA替代。结果表明,对照试样的抗压强度最高,为49.83 MPa,当RHA取代量为5%时,抗压强度开始下降。抗压强度随RHA用量从10%增加到15%而降低。抗折强度数据表明,10% RHA的抗折强度最大值为4.90 MPa。最小值为3.85 MPa,仅在5%的RHA中可见。由此可以推断,水泥中RHA置换水平为5%时,抗压强度显著提高。
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引用次数: 0
Evaluating and Predicting Overall Equipment Effectiveness for Deep Water Disposal Pump using ANN- GA Analysis Approach 基于神经网络-遗传算法的深水处理泵设备整体效能评估与预测
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22063
Soud Al-Toubi
This study proposes the Artificial Neural Network with a Genetic Algorithm analysis approach to investigate the Overall Equipment Effectiveness of the deep-water disposal pump system. The ANN-GA model was developed based on six big losses over eighteen successive months of the operating period to evaluate the current and future performance of the DWD system. 70% of the data was used for training and 15% for each data validation and testing. The DWD system faces frequent failure issues, significantly impacting its performance, so it is important to reveal the main causes of these failures to manage them properly. ANN-GA is applied to make a linear trend prediction and assesses the confidence and accuracy of the results obtained. Analysis of ANOVA (variance) was adopted as an additional decision tool for detecting the variation of process parameters. ANN-GA results showed that the current OEE value ranges between 29% to 54%, whereas the predicted future system performance average is approximately 49%, which reflects the poor performance of the DWD pump system in the future compared to the world- class target (85%). ANN-GA analysis results indicated were very close and matched with the actual values. The model framework and analysis presented are used to develop a decision support tool for managers for early intervention to minimize system deterioration, reduce maintenance costs and increase productivity. Furthermore, it allows early identifying the potential area ofimprovement to support continuous improvement (CI) objectives by identifying and eliminating unnecessary maintenance activities. The proposed model framework uses the ANN approach to identify the current state and predict the future of the system performance to ensure confidence in the results. The contribution of the paper will be helpful for experts like managers, reliability engineers, and maintenance engineers to identify the state of the system's performance in advance.
本文提出了基于遗传算法的人工神经网络分析方法来研究深水处理水泵系统的整体设备有效性。ANN-GA模型是基于连续18个月的6次重大损失开发的,用于评估DWD系统当前和未来的性能。70%的数据用于训练,15%用于每个数据的验证和测试。DWD系统面临频繁的故障问题,严重影响其性能,因此揭示这些故障的主要原因以进行适当的管理非常重要。应用ANN-GA进行线性趋势预测,并对预测结果的置信度和准确性进行评估。采用方差分析(ANOVA)作为检测工艺参数变化的附加决策工具。ANN-GA结果显示,当前的OEE值在29%到54%之间,而预测的未来系统性能平均值约为49%,这反映了与世界级目标(85%)相比,DWD泵系统未来的性能较差。ANN-GA分析结果与实际值非常接近。所提出的模型框架和分析用于为管理者开发决策支持工具,用于早期干预,以最大限度地减少系统恶化,降低维护成本并提高生产率。此外,它允许早期识别潜在的改进领域,通过识别和消除不必要的维护活动来支持持续改进(CI)目标。提出的模型框架使用人工神经网络方法来识别当前状态并预测系统性能的未来,以确保结果的置信度。本文的贡献将有助于管理人员、可靠性工程师和维护工程师等专家提前识别系统的性能状态。
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引用次数: 0
Optimization of Uniaxial Tensile Stress-Strain Response of 3D Angle Interlock Woven Fabric Composite using Weft Density and Draw-In Plan Variables 利用纬纱密度和拉拔平面变量优化三维角度互锁机织复合材料单轴拉伸应力-应变响应
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22062
M. F. Yahya
Currently, 2D woven composites are extensively incorporated into a variety of technical automotive body parts and protective body armor owing to their excellent fabric strength performance. However, there is still a lack of attempts to utilize 3D woven fabrics for the same technical application. Hence, it is vital to examine the fundamental tensile strength of woven fabric composite materials when determining their suitability for end-use applications. This study aimed to investigate the novel effects of two parameters on the uniaxial tensile strength of a high-tenacity polyester three-layer 3D angle interlock (3DAI) woven fabric composite, namely, weave drafting draw-in insertion and weave density. Four different drafting patterns were considered: pointed (DRW 1), broken (DRW 2), broken mirror (DRW 3), and straight (DRW 4), for weft density at 14 and 25 pick.cm-1. Samples of the 3DAI woven fabric reinforced with epoxy composite at different drafting patterns and weft density combinations were produced and tested. Consequently, the maximum tensile stress and strain were recorded in the woven fabric composite sample with DRW 4 and 25 pick.cm-1 at 113 MPa and 11%, respectively. The study shows that different weft densities and draw-in plan settings play a significant role in the tensile strength performance of the 3DAI woven composite.
目前,二维编织复合材料由于其优异的织物强度性能,被广泛应用于各种技术汽车车身部件和防护装甲中。然而,在同样的技术应用中,仍然缺乏利用3D机织物的尝试。因此,在确定机织复合材料是否适合最终用途时,检查其基本抗拉强度至关重要。本研究旨在探讨两个参数对高强涤纶三层三维角互锁(3DAI)机织物复合材料单轴拉伸强度的新影响,即组织牵伸、拉伸和组织密度。考虑了四种不同的牵伸模式:尖(DRW 1),破(DRW 2),破镜(DRW 3)和直(DRW 4),纬纱密度为14和25 pick.cm-1。制作并测试了环氧复合材料增强3DAI机织织物在不同牵伸图案和纬密度组合下的样品。结果表明,采用drw4和25挑片的机织物复合材料试样的最大拉伸应力和应变均得到了记录。在113 MPa下cm-1和11%。研究表明,不同纬密度和拉拔方案设置对3DAI机织复合材料的拉伸强度性能有显著影响。
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引用次数: 0
Evaluation of Energy Production using Parabolic-Dish Solar Collector: A Case Study of Iraq 利用抛物面式太阳能集热器发电的评价:以伊拉克为例
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22057
Itimad D. J. Azzawi
The parabolic dish reflector solar collector is one of the significant and most efficient steam-producing solar concentrating systems in thermoelectric power plants and, furthermore, it's considered to be environmentally friendly (renewable energy). Iraq has vast land for installing solar collectors to generate steam and use for thermal power plants. However, no such application/power plant has yet been built. Therefore, the proposed study investigates opportunities for using PDR solar collectors, including all advantages and challenges. To implement and estimate the productivity and efficiency of the PDR in (Diyala City / Iraq), a PDR solar collector with a total area of 0.708 m2 (including the glass pieces used as a reflective surface) was designed and fabricated. These glass pieces have been utilized to increase the reflection of solar rays by 80% when compared to a traditional case/setup. Two different systems (open and closed) were considered to investigate the performance of thermal power . The results show that the absorption temperature was increased from 34.6 to 95 °C. On the other hand, the coefficient of heat loss by convection increases by about (795.5 W). In addition, it was pointed out that the coefficient of total heat loss over time was increased by about 25 to 41% (closed and open systems). Furthermore, the experimental findings clearly demonstrate the usefulness of PDR solar heaters in Iraq. Hence, its confidently believed that this research will be useful in the future for this type of thermal power plant.
抛物面反射式太阳能集热器是热电厂中最重要和最有效的蒸汽产生太阳能集中系统之一,此外,它被认为是环保的(可再生能源)。伊拉克拥有广阔的土地,可以安装太阳能集热器,产生蒸汽,用于火力发电厂。然而,目前还没有这样的应用/发电厂建成。因此,提出的研究调查了使用PDR太阳能集热器的机会,包括所有的优势和挑战。为了在(迪亚拉市/伊拉克)实施和评估PDR的生产力和效率,设计并制造了一个总面积为0.708 m2的PDR太阳能集热器(包括用作反射表面的玻璃片)。与传统的案例/设置相比,这些玻璃片被用来增加80%的太阳光线反射。考虑了两种不同的系统(开式和闭式)来研究火电的性能。结果表明,吸收温度由34.6℃提高到95℃。另一方面,对流热损失系数增加了约795.5 W。此外,总热损失系数随时间增加了约25 ~ 41%(封闭和开放系统)。此外,实验结果清楚地表明PDR太阳能加热器在伊拉克的有用性。因此,我们有信心地相信,这项研究将在未来对这种类型的火力发电厂有用。
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引用次数: 0
Effects of Pre-Treated Crumb Rubber as Sand Partial Replacement on Compressive Strength of Engineered Cementitious Composites (ECC) 预处理橡胶屑部分替代砂对工程胶凝复合材料抗压强度的影响
IF 1.1 Pub Date : 2023-04-15 DOI: 10.24191/jmeche.v20i2.22060
A. Abdul Aziz
This study was conducted to determine the surface morphology of crumb rubber (CR) treated with 10% Sodium Hydroxide (NaOH) solution at different periods and the compressive strength of the treated rubberised engineered cementitious composites (R-ECC). R-ECC is a type of engineered cementitious Composite (ECC) with CR as partial sand replacement. In contrast to the quasi-brittle nature of conventional concrete, engineered cementitious Composite (ECC) is distinguished for its tensile strain-hardening behaviour and tensile ductility. However, adding crumb rubber (CR) in ECC as partial sand replacement reduces the composites’ compressive strength owing to its smooth surface. The Scanning Electron Microscopy (SEM) test was conducted on the CR samples, which had been treated with 10% NaOH for 1, 2 and 3 days. Meanwhile, the compressive strength test was conducted on 45 cubes consisting of standard ECC, untreated R-ECC and treated R-ECC. The results discovered that 2 and 3 days of 10% NaOH treatment on CR enhanced its surface roughness, and 2 days NaOH treated R-ECC is the optimum duration for the highest compressive strength reduction. Therefore, the enhanced surface roughness of the CR used as partial sand replacement in the ECC can lessen the compressive strength reduction owing to better bonding between CR and cement matrix in the composites.
研究了10%氢氧化钠(NaOH)溶液处理不同时间下橡胶屑(CR)的表面形貌以及处理后的橡胶工程胶凝复合材料(R-ECC)的抗压强度。R-ECC是一种以CR代替部分砂石的工程胶凝复合材料(ECC)。与传统混凝土的准脆性相反,工程胶凝复合材料(ECC)以其拉伸应变硬化行为和拉伸延性而闻名。然而,在ECC中加入颗粒橡胶(CR)作为部分替代砂,由于其表面光滑,降低了复合材料的抗压强度。对经10% NaOH处理1、2、3天的CR样品进行扫描电镜(SEM)检测。同时,对标准ECC、未经处理的R-ECC和处理后的R-ECC组成的45个立方体进行了抗压强度试验。结果发现,10% NaOH处理CR 2和3 d均能提高CR的表面粗糙度,NaOH处理R-ECC 2 d的抗压强度降低幅度最大。因此,在ECC中部分替代砂石的CR的表面粗糙度提高,可以减轻复合材料中CR与水泥基体之间更好的粘结,从而减少抗压强度的降低。
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引用次数: 0
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Journal of Mechanical Engineering and Sciences
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