本文選題：導(dǎo)電水泥基材料 + 力學(xué)性能��； 參考：《南京航空航天大學(xué)》2017年碩士論文

【摘要】：建筑工程在服役過程中,受到外部荷載的作用會(huì)產(chǎn)生損傷和承載力下降等問題,易引起突發(fā)性事故。因此,實(shí)時(shí)監(jiān)測這些工程材料的損傷程度有很大價(jià)值。傳統(tǒng)的監(jiān)測方法主要有內(nèi)置傳感器,但該方法造價(jià)高、耐久性能差、對(duì)使用環(huán)境限制較多,阻礙和影響了該方法的建設(shè)應(yīng)用。導(dǎo)電水泥基材料就是在水泥基材料中摻具有導(dǎo)電性的功能材料,通過在內(nèi)部形成連續(xù)的導(dǎo)電網(wǎng)絡(luò),使其具備感應(yīng)自身變形和損傷的功能,為實(shí)時(shí)監(jiān)測結(jié)構(gòu)內(nèi)部損傷及使用狀態(tài)提供了新的可能性。本文研究了導(dǎo)電水泥基材料的力-電及機(jī)敏性,具體研究內(nèi)容及結(jié)論如下:研究了摻不同功能材料對(duì)水泥漿體、砂漿導(dǎo)電性能的影響。水泥漿體電阻率隨功能材料摻量增大而減小,功能材料C水泥漿體滲流閾值約為1.0%,功能材料G水泥漿體滲流閾值約為10%,功能材料G替代功能材料C時(shí),水泥漿體28d電阻率隨替代比例的增大先減小再增大再減小再增大;改性導(dǎo)電水泥漿體的電阻率隨聚灰比增大而增大,力學(xué)性能隨聚灰比的增大先增大后減小;水泥砂漿中功能材料G替代功能材料C的最佳比例約為25%,改性導(dǎo)電水泥砂漿最佳聚灰比為0.02。研究了摻功能材料C和G混凝土的機(jī)敏性�；炷猎嚇釉谑軌哼^程中隨壓力增大,試塊的電阻率呈現(xiàn)下降、平衡和劇增三個(gè)階段,反映混凝土內(nèi)部結(jié)構(gòu)缺陷裂紋閉合、裂紋產(chǎn)生和破壞;混凝土摻入聚合物后平衡階段增長,說明摻聚合物可抑制混凝土新裂縫的產(chǎn)生;循環(huán)荷載下,在每個(gè)周期的加壓階段混凝土電阻率持續(xù)減小,卸載后電阻率增大,每個(gè)循環(huán)內(nèi)的變化規(guī)律基本一致;摻0.75%功能材料C和2.5%功能材料G的導(dǎo)電混凝土受彎機(jī)敏性較好,電阻變化率達(dá)到8.60%。用ANSYS模擬摻功能材料導(dǎo)電混凝土的溫度場分布,可知溫度由中心位置向四周逐漸降低,中心位置溫度高達(dá)47.36℃,邊緣角點(diǎn)位置為41.72℃;對(duì)比試驗(yàn)結(jié)果與模擬結(jié)果,間接證明了該分析方法的適用性;模擬分析了導(dǎo)電混凝土在加熱過程中的變形和應(yīng)力應(yīng)變,混凝土的變形主要是從中心位置呈環(huán)狀向四周逐漸增大,最大變形出現(xiàn)在四個(gè)角點(diǎn)的位置,為0.13mm,最小變形位于上表面中心位置,為0.89×10~(-3)mm。
[Abstract]:In the service process of building engineering, damage and bearing capacity will be decreased due to external load, which can easily lead to sudden accidents. Therefore, it is of great value to monitor the damage degree of these engineering materials in real time. The traditional monitoring methods mainly have built-in sensors, but this method has high cost, poor durability, and has a lot of limitations on the use of the environment, which hinders and affects the construction and application of the method. Conductive cement-based material is a kind of functional material with electrical conductivity, which can induce its own deformation and damage by forming a continuous conductive network inside the material. It provides a new possibility for real-time monitoring of internal damage and operating state of the structure. In this paper, the mechano-electric and smart properties of conductive cement-based materials are studied. The specific contents and conclusions are as follows: the effects of different functional materials on the conductive properties of cement paste and mortar are studied. The resistivity of cement paste decreases with the increase of the content of functional material. The percolation threshold of functional material C cement paste is about 1.0 and that of functional material G cement paste is about 10. When the functional material G replaces the functional material C, the cement paste resistivity decreases with the increase of the content of the cement paste. The resistivity of the modified conductive cement paste first decreases and then decreases and then increases with the increase of the substitution ratio, and the resistivity of the modified conductive cement paste increases with the increase of the cement aggregate ratio, and the mechanical properties increase first and then decrease with the increase of the aggregate cement ratio. The optimum ratio of functional material G to functional material C in cement mortar is about 25 and the optimum cement cement ratio of modified conductive cement mortar is 0.02. The cleverness of concrete mixed with functional materials C and G was studied. The resistivity of concrete specimen decreases, equilibrium and sharp increase with the increase of pressure, which reflects the crack closure, crack generation and failure of concrete internal structure. The increase of equilibrium stage after adding polymer into concrete shows that polymer admixture can restrain the occurrence of new cracks in concrete, and under cyclic load, the resistivity of concrete decreases continuously at the compression stage of each cycle, and increases after unloading. The flexural sensitivity of conductive concrete mixed with 0.75% functional material C and 2.5% functional material G is good, and the change rate of resistance is 8.60%. The temperature field distribution of conductive concrete doped with functional materials is simulated by ANSYS. The temperature decreases gradually from the center position to the surrounding direction, the central temperature reaches 47.36 鈩，

本文編號(hào)：1841690