酚醛树脂对膨胀玻化微珠包覆改性研究

将热固性酚醛树脂包覆在膨胀玻化微珠的表面形成增强层,制备了酚醛树脂增强改性的膨胀玻化微珠.研究酚醛树脂用量对改性膨胀玻化微珠的堆积密度、体积吸水率、导热系数和筒压强度的影响.结果表明,改性后的膨胀玻化微珠的堆积密度、筒压强度随着酚醛树脂含量的增加呈上升趋势,其体积吸水率降低,导热系数变化不大.     

高性能玻化微珠保温砂浆的制备

由于拌合过程中膨胀玻化微珠破碎率较高,采用目前大量应用的堆积密度120kg/m3～160kg/m3的III类膨胀玻化微珠,制备出的II型保温砂浆的干密度通常为350kg/m3～400kg/m3,导热系数大于0.085W/（m·K）,而干燥收缩值高达2mm/m～3mm/m,导致保温砂浆热工性能下降且易开裂。因此,有效降低玻化微珠破碎率是利用III类膨胀玻化微珠制备干密度小于300kg/m3的I型保温砂浆的关键。采用引气剂与羟丙基甲基纤维素醚复配技术并掺加减水剂,有效地提高玻化微珠保温砂浆拌合物的和易性,降低玻化微珠的破碎率;掺加半水石膏等膨胀组分,可以有效降低保温砂浆的干燥收缩。试验采用堆积密度150kg/m3～160kg/m3的III类膨胀玻化微珠制备出的高性能保温砂浆,其干密度小于300kg/m3,抗压强度可达0.9MPa～1.1MPa,导热系数低于0.07W/（m·K）,干燥收缩值低至0.3mm/m～0.5mm/m,具有优异的热工性能、力学性能和抗裂性。     

膨胀玻化微珠保温板性能试验研究

以膨胀玻化微珠为主要原料,与水泥、外加剂混合,经模压成型制备新型保温墙板。通过正交试验,测试膨胀玻化微珠、水泥、外加剂种类、纤维水镁石绒掺量对膨胀玻化微珠墙体保温板抗压强度和导热系数的影响。结果显示:膨胀玻化微珠掺量对保温板导热系数影响显著,对保温板强度的影响因素顺序为:膨胀玻化微珠掺量外加剂种类水泥用量纤维水镁石绒掺量。     

酸固化剂对酚醛树脂/玻化微珠复合材料性能的影响

以酚醛树脂和玻化微珠为主要原料,在特定条件下酸催化固化成型,制备酚醛树脂/玻化微珠轻质复合材料。通过单因素法研究了单酸与混酸固化剂对酚醛树脂/玻化微珠复合材料性能的影响。结果表明,使用盐酸和磷酸质量比为2∶1,且占酚醛树脂质量12%的混酸作固化剂时,复合材料性能最优,其抗压强度为1.287 MPa,密度为328 kg/m3。     

玻化微珠保温砂浆配合比的正交试验研究

通过正交试验,研究了膨胀珍珠岩与玻化微珠复合骨料、粉煤灰、聚丙烯纤维和引气剂对保温砂浆的物理、力学性能以及保温性能的影响。用膨胀珍珠岩与玻化微珠按适宜比例配合组成复合骨料来制备保温砂浆,可有效改善骨料颗粒级配,降低砂浆的干密度,提高强度。掺加粉煤灰,不仅可降低砂浆的干密度,而且可有效降低成本。在砂浆中掺入聚丙烯纤维可有效提高砂浆的抗折强度。引气剂的掺入可以进一步降低砂浆的干密度,改善其保温性能,同时也可提高砂浆的流动性。     

关键组分对高聚物乳液基酚醛树脂粉玻化微珠复合保温浆料性能的影响研究

通过试验考察了乳液种类及用量、玻化微珠的级配和用量、酚醛树脂粉的用量、疏水剂的种类和用量对高聚物乳液基酚醛树脂粉玻化微珠复合保温浆料的抗压强度、压剪黏结强度、软化系数、热导率、吸水率等主要性能的影响规律,确定了高聚物乳液基酚醛树脂粉玻化微珠复合保温浆料的最优配方。本产品克服了常用有机、无机保温材料的缺点,具有燃烧性能好、热导率低、吸水率低、生产工艺和施工工艺简单、造价成本低等优点。     

复合轻质骨料保温抹灰砂浆的制备与性能研究

利用膨胀玻化微珠和空心微珠为轻质骨料制备了复合轻质骨料保温抹灰砂浆,研究了水泥用量和轻质骨料组成对保温抹灰砂浆性能的影响。结果表明:随胶集比提高,保温抹灰砂浆的抗压强度和导热系数均逐步增大,但增幅不同;以空心微珠等体积取代膨胀玻化微珠,随空心微珠取代率提高,保温抹灰砂浆的抗压强度显著提高,导热系数小幅增大。     

阻燃耐热型玻化微珠/聚氨酯硬泡复合保温材料的制备和性能研究

通过原位发泡法,将聚氨酯原料与无机玻化微珠及阻燃剂复合制备了一种高填料含量的玻化微珠/聚氨酯泡沫复合材料(GHB-PUF).采用氧指数、导热系数、压缩强度和热重分析分别表征玻化微珠掺量对聚氨酯泡沫复合材料的阻燃性能、导热性能、压缩性能和热稳定性能的影响.结果表明,高掺量的玻化微珠和适量阻燃剂的引入使得复合材料的阻燃性能和压缩强度能显著提高,极限氧指数可达30％以上,并且随着玻化微珠掺量的增加而增大,压缩强度达0.17 MPa;材料保温性能略有降低,导热系数为0.045 W/(m·K),但仍适用于墙体保温材料;热稳定性明显改善,材料热解的外延起始温度升高至263℃,800℃残余量为61.56％.     

玻化微珠发泡保温板正交试验研究

玻化微珠发泡保温板是一种导热系数低、A级防火的新型无机保温板材.试验对原材料对玻化微珠发泡保温板性能的影响规律进行了研究,确定了其最优配合比.采用三因素三水平正交试验方法,测定不同玻化微珠、二氧化硅气凝胶和外加剂掺量下的玻化微珠发泡保温板导热系数和抗压强度.试验结果表明:影响玻化微珠发泡保温板导热系数和抗压强度的因素顺序为:玻化微珠＞二氧化硅气凝胶＞外加剂.玻化微珠对导热系数影响显著,二氧化硅气凝胶和适量外加剂可弥补保温材料掺量增加引起的强度损失.     

玻化微珠-膨胀珍珠岩保温板的性能研究

采用玻化微珠和膨胀珍珠岩制备无机保温板,研究其导热系数、抗压强度和干密度分别随玻化微珠掺量的变化规律。结果表明,玻化微珠的较佳掺量为膨胀珍珠岩质量的30%,与未掺加玻化微珠的膨胀珍珠岩保温板相比,其导热系数降低了14.7%,抗压强度提高了17.8%,干密度增加了19.9%。利用扫描电子显微镜对试样进行微观分析,探讨玻化微珠掺量对保温板性能的影响。     

短切玄武岩纤维混凝土基本力学性能的尺寸效应

为了研究短切玄武岩纤维混凝土试件尺寸变化对其基本力学性能的影响,对不同纤维长度（15,25 mm）、纤维体积掺量（0.1%,0.2%）、基体混凝土强度等级（C30,C40）的330个短切玄武岩纤维混凝土（BFRC）试件分别进行了立方体抗压强度、轴心抗压强度、劈裂抗拉强度、弯曲抗拉强度试验并对试验数据处理,以尺寸效应度反映尺寸效应规律。研究结果表明:玄武岩纤维混凝土立方体抗压强度试件的尺寸换算系数受混凝土的强度等级、纤维长度、纤维体积掺量的影响较小;轴心抗压强度的尺寸效应随混凝土强度等级、纤维长度、纤维体积掺量的增大均有所提高;劈裂抗拉强度随混凝土强度等级变化,其尺寸效应不明显,但随纤维长度的减小及纤维体积掺量的增加,尺寸效应有增大趋势;混凝土强度等级和纤维长度的改变对混凝土弯曲抗拉强度的尺寸效应影响不大,但随纤维体积掺量的增加,尺寸换算系数先减小后变大。     

Mechanical properties of steel,glass, and hybrid fiber reinforced reactive powder concrete

This study examines the properties of fiber-reinforced reactive powder concrete (FR-RPC). Steel fibers, glass fibers, and steel-glass hybrid fibers were used to prepare the FR-RPC. The non-fibrous reactive powder concrete (NF-RPC) was prepared as a reference mix. The proportion of fibers by volume for all FR-RPC mixes was 1.5%. Steel fibers of 13 mm length and 0.2 mm diameter were used to prepare the steel fiber-reinforced RPC (SFR-RPC). Glass fibers of 13 mm length and 1.3 mm diameter were used to prepare the glass fiber-reinforced RPC (GFR-RPC). The hybrid fiber-reinforced RPC (HFR-RPC) was prepared by mixing 0.9% steel fibers and 0.6% glass fibers. Compressive strength, axial load-axial deformation behavior, modulus of elasticity, indirect tensile strength, and shear strength of the RPC mixes were investigated. The results showed that SFR-RPC achieved higher compressive strength, indirect tensile strength and shear strength than NF-RPC, GFR-RPC, and HFR-RPC. Although the compressive strengths of GFR-RPC and HFR-RPC were slightly lower than the compressive strength of NF-RPC, the shear strengths of GFR-RPC and HFR-RPC were higher than that of NF-RPC.     

Evaluation of natural and artificial fiber reinforcements on the mechanical properties of cement-stabilized dredged sediment

The combination of chemical stabilization and fiber reinforcement can simultaneously improve the strength and ductility of dredged sediment. The polypropylene fiber (PF) and straw fiber (SF) were respectively used as artificial and natural reinforcements of cement-stabilized dredged sediment (CDS). A series of unconfined compressive strength (UCS) tests were conducted to investigate the effects of cement content, fiber content, fiber length and water content on the mechanical properties of PF-reinforced CDS (CPFDS) and SF-reinforced CDS (CSFDS). Furthermore, the cementation-reinforcement mechanism was explored and analyzed via macro failure characteristics and micro interfacial morphologies inside typical CPFDS and CSFDS samples. The results showed that increasing cement content or decreasing water content significantly improved the UCS and aggravated the brittleness of CPFDS and CSFDS. The suitable addition of PF can effectively improve the UCS of CDS, while incorporating SF exhibited the opposite role. The maximum 7d-, 28d-, 60d- and 90d-UCS of CPFDS were respectively 17.7%, 43.6%, 10.7% and 9.7% higher than that of CDS. The optimum length of PF inside CPFDS and SF inside CSFDS was 3 mm and 5–10 mm, respectively. Both incorporating PF or SF can effectively improve the ductility of CDS. Based on the proposed parameters of total-water/cement ratio and fiber cementation factor, the effective strength development models of CPFDS and CSFDS considering cement content, fiber content, water content and curing time were empirically established. The fiber “bridge” effect and interfacial friction between fiber and cemented soil particles were mainly responsible for the strength evolution and ductility improvement of CPFDS and CSFDS.     

Effect of Temperature Exposure on the Flexural Mechanical Behavior of Two Pultruded Composites

The use of non-metallic composites at floor gratings in offshore platforms is driven by the need for increased component life in corrosive environments. As a result, these floor gratings contribute to a lower demand for maintenance and greater operational continuity. However, these composite materials have limitations when are exposed to high temperatures. The application of these floor gratings, on ships and floating offshore platforms have the requirement to retain a significant level of mechanical integrity during and after exposure to a fire. In this work, the mechanical behavior of two composites materials after being subject to a temperature rise was evaluated. One composite has an isophthalic polyester resin as matrix and the other used a phenolic resin. Before the mechanical characterization, thermogravimetric analysis was performed to determine the temperatures of beginning of the thermal degradation, and the microstructure of the composites was evaluated by digital image analysis. From the results of the thermal analysis a temperature of 250°C was chosen as the maximum one to be used, in order to evaluate the behavior of these composites in regions close to fire but not directly exposed to fire. Flexural properties of the two composites were performed by three-point bending test with 25 specimens of each composite. For the phenolic resin composite, the test specimens were manufactured with the average dimensions of 90.5 mm long, 19.5 mm large and 4.2 mm thick. The average dimensions of isophthalic composite specimens were 135.0 mm long, 25.0 mm large and 6.9 mm thick. The results show that the isophthalic resin matrix composite lost its mechanical integrity with the time of exposure to temperature, while the phenolic matrix composite maintained their properties. For example, regarding the maximum flexural stress a decrease of almost 50% was measured for the isophthalic matrix composite in comparison to only 3% for the phenolic matrix composite. However, the mechanical behavior of this composite was impaired by the presence of a high content of voids (5.7%) and of touching fibers arising from the manufacturing process.     

硫化碱废料制备改性材料的试验

随着世界日趋显现的木材短缺情况,发展非木质建筑材料成为国际关注的重点。煤炭、芒硝制备硫化碱生产过程中所产生的废料常年堆积,对环境造成巨大污染,依据目前市场对非木质复合板材的需求,并结合硫化碱生产废料自身不燃、无毒的性质,可考虑用做耐火材料的基材。选择硫化碱废料为复合板材的基础原料,就无机添加剂的选择及配比、酚醛树脂的量对抗压强度的影响、植物纤维对抗压强度的影响、发泡剂对试验的影响以及一些添加剂对样品的影响进行了相关试验。结果表明,当植物纤维∶硫化碱废料为1∶4,硫化碱废料∶石膏∶水泥为7∶6∶2,酚醛树脂的含量为10%,水分的加入量为12%,发泡剂的百分含量为0.15%,岩棉的含量为10%,三乙醇胺的含量为4%时,效果最佳。     

挤压纤维增强水泥板及复合梁抗弯与耐久性能

研究了水灰比、纤维种类、掺量和水泥基材对挤压成型纤维水泥板及其复合梁的力学性能与耐久性能的影响。结果表明掺加纤维后板材韧性有显著改善;PVA纤维增强板材当纤维掺量达1.7%时表现应变硬化,出现多点开裂;PP纤维则呈现应变软化。两种纤维增强水泥基材料性能的差异是由于纤维自身性能的不同。以纤维增强板为底板,制作的纤维板/混凝土复合梁的极限荷载和相应挠度,与普通混凝土梁相比都得以改善;同时与普通混凝土梁相比,复合梁的抗氯离子渗透性能更好。     

硼改性酚醛树脂的合成及其复合材料的性能

从催化剂用量、反应时间和温度等方面研究了合成工艺条件对硼改性酚醛树脂(BPR)性能的影响,研究了碳纤维/硼改性酚醛树脂(CF/BPR)复合材料性能与碳纤维含量及其表面处理的关系.结果表明:在特定的反应温度、时间和催化剂条件下,可以合成出性能良好的BPR.随着碳纤维含量的增加,CF/BPR复合材料弯曲强度、弯曲模量和冲击强度均逐渐增加;当碳纤维含量达到30%(质量分数)时,CF/BPR复合材料弯曲强度、弯曲模量和冲击强度达到最大值.CF/BPR复合材料弯曲强度和弯曲模量因碳纤维的表面处理而提高,但冲击强度却略有下降.     

新型水泥基复合保温板试验配比初探

试验以骨料聚苯颗粒、水泥、粉煤灰、激发剂和纤维为原料,采用模压法制备新型水泥基复合保温板。通过粉煤灰取代水泥最佳掺量的确定,研究粉煤灰掺量对复合保温板强度的影响;通过激发剂最佳掺量的确定,研究激发剂对复合保温板力学性能的影响;通过纤维最佳掺量的确定,研究纤维对复合保温板性能的影响。并通过扫描电镜观察试样内部微观形貌,研究各组分相关作用机理。     

一种轻质混合保温材料的性能研究

本文用聚苯乙烯泡沫塑料颗粒和酚醛树脂等制备了一种轻质混合保温材料,制备时进行了一定的压缩,得到了良好的抗压强度和保温性能,但其阻燃性还有待于进一步的提高.本文研究了该材料的力学性能和绝热性能,并重点探讨了颗粒直径、压缩比、酚醛树脂含量等对保温材料抗压强度、导热系数和氧指数的影响.