【摘要】：由于塑料制品的制備工藝越來越成熟,使得塑料的應用領(lǐng)域越來越廣泛。與此同時產(chǎn)生的廢舊塑料也與日俱增,且對環(huán)境造成的污染十分嚴重,甚至對人類的健康生活產(chǎn)生了不可忽視的威脅。因此越來越多的人們開始關(guān)注廢舊塑料的處理。塑料有很強的韌性,理論上塑料加入脆性的混凝土中可以改善混凝土的韌性,增加其抗震性,同時塑料質(zhì)輕,塑料的加入可以有效地降低混凝土的表觀密度等。因此研究塑料骨料對混凝土性能的影響是一項很有前景的項目,它有助于改善混凝土本身存在的不足,同時還可以為處理大量廢舊塑料尋找出一條新的途徑。本文以廢舊PVC電纜皮為塑料骨料原材料,經(jīng)破碎后部分與水泥粉混合再經(jīng)雙螺旋擠出機重新造粒,制得新骨料(在以后論文中沒有特殊說明時骨料專指制備的新骨料),采用內(nèi)摻等體積取代法用骨料取代砂漿中的砂制備塑料砂漿。以下幾個方面為本文研究的重點:1.用制備出的塑料骨料作為對象研究其屬性(表觀密度,接觸角,彈性模量等)與水泥含量的關(guān)系,實驗發(fā)現(xiàn)隨著水泥含量的增加,骨料的接觸角變小,表觀密度,彈性模量增加;2.將制得的骨料添加到砂漿中,研究不同含量的骨料對砂漿流動性、表觀密度、抗折抗壓強度、極限撓度、骨料分布的影響。實驗發(fā)現(xiàn):當骨料含量相等時,隨著骨料中水泥含量的增加,砂漿的抗折抗壓強度、極限撓度與骨料在砂漿中分布的均勻度變大;3.研究不同骨料含量對砂漿導熱性能的影響,并建立并聯(lián)串聯(lián)模型,假設并聯(lián)因子與串聯(lián)因子,導出理論導熱系數(shù)與骨料含量的關(guān)系。實驗發(fā)現(xiàn)砂漿試樣的導熱系數(shù)隨著骨料的增加而減小,理論并聯(lián)導熱系數(shù)大于串聯(lián)導熱系數(shù);4.以孔徑均勻性指標α與孔徑均值r為參數(shù)研究不同溫度下不同骨料含量對砂漿孔結(jié)構(gòu)的影響及其對砂漿抗硫酸鹽性能的影響,在200℃條件下隨著骨料含量的增加,α變大,r減小,經(jīng)熱處理后砂漿抗硫酸鹽的侵蝕能力得到增強。
[Abstract]:As the preparation technology of plastic products becomes more and more mature, the application field of plastics becomes more and more extensive. At the same time, the waste plastics are increasingly produced, and the pollution to the environment is very serious, even to the health of human life has produced a threat that can not be ignored. Therefore, more and more people begin to pay attention to the treatment of waste plastics. Plastic has a strong toughness. In theory, adding plastic to brittle concrete can improve the toughness of concrete and increase its seismic resistance. At the same time, the plastic is light, and the addition of plastic can effectively reduce the apparent density of concrete. Therefore, it is a promising project to study the influence of plastic aggregate on concrete performance, which is helpful to improve the shortcomings of concrete itself, and to find a new way to deal with a large number of waste plastics at the same time. In this paper, the waste PVC cable skin is used as the raw material of plastic aggregate, after crushing part is mixed with cement powder and then granulated by double helix extruder, the new aggregate is prepared (when there is no special explanation in the later paper, the new aggregate is specially prepared). The plastic mortar was prepared by replacing the sand in the mortar with aggregate by the method of equal volume substitution. The following aspects are the focus of this study: 1. The relationship between the properties (apparent density, contact angle, elastic modulus, etc.) and the cement content was studied by using the prepared plastic aggregate as the object. It was found that the contact angle and apparent density of the aggregate decreased with the increase of cement content. The elastic modulus increases; 2. The effects of different contents of aggregate on the flowability, apparent density, flexural strength, ultimate deflection and aggregate distribution of the mortar were studied. It is found that when the aggregate content is equal, with the increase of cement content in aggregate, the flexural strength, ultimate deflection and uniformity of aggregate distribution in mortar become larger; 3. The influence of different aggregate content on the thermal conductivity of mortar was studied, and a parallel series model was established. The relationship between theoretical thermal conductivity and aggregate content was deduced by assuming the parallel factor and series factor. It is found that the thermal conductivity of mortar samples decreases with the increase of aggregate, and the theoretical parallel thermal conductivity is larger than that of series. 4. The effect of different aggregate content on the pore structure of mortar at different temperatures and its effect on the sulphate resistance of mortar were studied by using the pore size uniformity index 偽 and the mean pore diameter r as parameters. At 200 鈩，

本文編號：2384810