共查询到18条相似文献，搜索用时 828 毫秒
1.
本文以不同掺量的水泥、氢氧化钠,氢氧化钙,硫酸钠作为碱激发剂,激发粉煤灰胶凝材料的活性,试验结果表明,30%-40%的水泥、2.5%的Ca(OH)2和2.0%Na2SO4复掺后,粉煤灰试块28d的抗折,抗压强度均能达到全掺水泥基准砂浆的相同龄期强度.本研究应用于工程,可减少水泥熟料的掺入,降低混凝土的配制成本. 相似文献
2.
为了研究尾矿粉掺加水泥稳定铁矿废石混合料施工最佳配合比的影响,对不同掺量尾矿粉(0%、5%、10%、15%、20%)及不同种类和剂量外加剂的水泥稳定铁矿废石混合料进行无侧限抗压强度、水稳性、抗冻性、疲劳性能试验,试验结果表明,随着尾矿粉掺量增加水泥稳定铁矿废石混合料无侧限抗压强度、水稳定系数、抗冻系数呈现先增加后降低变化趋势,当尾矿粉掺量达到14.5%时,混合料无侧限抗压强度、水稳定系数、抗冻系数达到峰值;当尾矿粉掺量为6.3%时,混合料疲劳性能达到最佳;尾矿粉掺入水泥稳定铁矿废石混合料剂量为15%时,可以广泛应用于道路基层中。 相似文献
3.
污水处理厂污泥固化及影响因素的试验研究 总被引：1，自引：0，他引：1
通过对2种含水率的污水处理厂污泥采用石灰与粘土或水泥与粘土进行固化,测试不同龄期和掺量下固化污泥的无侧限抗压强度.研究发现:固化强度随龄期和掺量增大均增大,且相同条件下,水泥的固化效果要好于石灰,前者固化强度约是后者的2～5倍;龄期较短时,粘土对固化强度影响明显,龄期较长时,石灰或水泥的影响明显.短龄期内提高固化材料的掺量,对于强度提高不明显;污泥含水率由92.1%减小到53.1%时,强度增大2～10倍.最后,建立固化强度预测模型,预测含水率相近污泥的固化强度. 相似文献
4.
陈三姗陈峰 《福建工程学院学报》2021,(1):61-67
从粉煤灰-水泥相互作用、粉煤灰-淤泥质土相互作用两个方面开展一系列试验,研究粉煤灰对水泥和淤泥质粘土的强度及固化过程的影响,然后通过扫描电镜(SEM)试验,观察粉煤灰水泥土的微结构变化以探究其机理。粉煤灰水泥石强度试验表明粉煤灰能使水泥石28d及以上龄期的强度提高,粉煤灰淤泥质土的含水率试验和固结不排水试验表明,粉煤灰使淤泥土的硬度变大,X射线衍射(XRD)试验表明粉煤灰能细化水泥中Ca(OH)2晶粒,SEM试验结果表明粉煤灰可以使水泥土的微结构更加密实。 相似文献
5.
温州软土水泥土抗压强度与养护龄期、水泥掺合量的关系 总被引：2，自引：0，他引：2
潘林有 《温州大学学报(社会科学版)》2002,15(3):68-71
本文通过温州粘土、淤泥质粘土和水泥混合产生的水泥土的室内抗压强度试验，找到了水泥土抗压强度与水泥掺量、养护龄期三者的相关性（经验公式），对水泥深层搅拌法的应用具有一定的指导作用。 相似文献
6.
赵建红 《北京工业职业技术学院学报》2006,5(3):54-58,115
通过对水泥土块强度试验,分析了影响夯实水泥土桩强度的主要因素,并详细论证了水泥掺入比、土的种类、桩体干密度及养护龄期等因素与水泥土桩体强度之间的关系. 相似文献
7.
高掺量矿渣粉煤灰复合水泥的研制 总被引：1，自引：0，他引：1
根据不同类型混合材之间性能上的差异,通过两种或两种以上混合材的复掺,可以取得性能上优于任何一种单掺时的效果,即“优势互补效应”.本文对矿渣和粉煤灰的优势互补效应进行了研究,并采用适当的外加剂来提高水泥的早期强度.研究结果表明,通过混合材的合理搭配,即使粉煤灰掺量达28%,混合材总掺量为70%,水泥各龄期强度仍能满足425R~#复合水泥的要求. 相似文献
8.
生态型RPC材料在静态和动态荷载下的力学行为研究 总被引：1，自引：0，他引：1
以50%～60%的超细工业废渣取代水泥,用天然黄砂取代磨细石英砂,采用超细工业废渣多元复合技术,制备出生态型活性粉末混凝土(ECO-RPC).研究了不同纤维掺量和不同养护龄期对ECO-RPC静态力学性能的影响.采用霍普金森杆方法研究了高速冲击下应变速率对ECO-RPC动态力学性能的影响.结果表明,随着纤维掺量和养护龄期的增加,ECO-RPC各项静态力学性能不断提高.通过超细粉煤灰(25%)、超细矿粉(25%)和硅灰(10%)三掺制备的ECO-RPC性能最佳,其抗压强度、抗折强度和断裂能分别达到200 MPa,60 MPa 和 30 kJ/m2以上.ECO-RPC具有明显的应变率强化效应,随着应变率的提高,峰值应力及峰值应变显著增长,应力应变曲线所包围的面积不断增大,破坏特征从脆性转变为韧性. 相似文献
9.
陈宝璠 《福建工程学院学报》2012,10(6):552-558
采用自制的MPEGAA-AA-AMPS高效减水剂和P(AA-co-MA)/PEG、FDN-A减水剂,以不同掺量掺入P.O 42.5普通硅酸盐水泥,运用混凝土外加剂匀质性试验方法和水泥胶砂强度检验方法,研究不同掺量对水泥净浆流动度、水泥砂浆减水率、水泥净浆泌水率以及水泥砂浆的抗压强度等性能的影响,并利用电镜对添加MPEGAA-AA-AMPS高效减水剂的硬化水泥石的内部结构进行表征。结果显示,MPEGAA-AA-AMPS高效减水剂掺量为1.0%时,水泥净浆流动度达322 mm,砂浆减水率为47%,泌水率仅1.1%,28 d水泥胶砂抗压强度可达67.9 MPa。可见MPEGAA-AA-AMPS高效减水剂无论对水泥净浆或水泥砂浆的分散能力、保水性能和减水作用,还是对力学强度均有明显优势。从水泥石的内部结构SEM图看,添加MPEGAA-AA-AMPS高效减水剂后更能保证水泥石的抗压强度和经时耐受力。 相似文献
10.
《实验室研究与探索》2019,(11)
将木质素掺入花岗岩残积土,通过击实和单轴压缩试验,对比研究了木质素掺量和含水率变化对土样压实性和单轴抗压强度特性的影响。结果表明:在试验范围内,掺入木质素后,花岗岩残积土土样干密度对含水率的敏感性增大;随着木质素掺量的增加,各土样的最优含水率先降低后升高,最大干密度先增大后减小。随着含水率的减小,花岗岩残积土土样的单轴抗压强度逐渐增大;随着木质素掺量的增加,在较高含水率下,各土样单轴抗压强度总体上呈下降的趋势,在较低含水率下土样的强度得到有效提高。 相似文献
11.
This paper presents an investigation on strength of cement deep mixing (CDM) mixture.Four typical works of offshore or land-based projects are introduced. With samples from these projects and laboratory tests, statistical analysis is made on the increment law of the strength of cement-soil mixture with different amount of cement, and strengths under different working conditions are compared. It is found that the amount of cement in the cement-soil mixture is closely related to the unconfined compressive strength of the mixture. At the age of 90 d,the unconfined compressive strength of the cement-soil mixture increased by 0.054 MPa-0.124MPa with each cement increasing 10 kg/m^3 in the cement-soil mixture, averagely increased by 0.085 MPa, while that at the age of 120 d increased by 11% in comparison. The quality of the cement-soil mixture should be comprehensively evaluated in accordance with the trimmed average of strength, coefficient of variation and rock quality designation (RQD) indicators of sampling ratio. 相似文献
12.
以超细钢铁渣粉(以下简称“超细钢渣”) 为主要掺合料制备胶凝材料,通过XRF、粒径分析、XRD分析和力学性能测试,探究超细钢渣对水泥基材料的力学性能影响。结果表明:通过机械研磨制备出的超细钢渣,其矿相成分硅酸三钙、硅酸二钙和莫来石特征峰强度最强,复掺的超细钢渣活性指数也满足国家标准。随着超细钢渣掺量增加,3 d 抗压和抗折强度均出现逐渐降低的趋势,但在外掺m (超细钢渣) ∶ m (超细矿渣)= 2:3、w复合粉=30%时,其28 d 抗压和抗折强度达到峰值,分别为8.9、53.8 MPa。超细钢渣在不同龄期水化反应程度不同,早期水化反应较低,强度较差;后期水化程度较高,且优于同标准水泥。 相似文献
13.
以硅酸盐和硫铝酸盐复合水泥为基材制作水泥基注浆材料,分别讨论了不同类型、不同掺量的粉煤灰和矿粉对水泥基注浆材料的流动度、容重、膨胀率、抗压抗折强度的影响。结果表明:粉煤灰能有效地增加水泥基注浆料的流动度,当粉煤灰掺量低于20%时,可以提高注浆料的塑性膨胀率,当Ⅰ级粉煤灰掺量为20%或Ⅱ级粉煤灰掺量为15%时,3 h膨胀率最高达1%;粉煤灰对注浆料的早期强度不利,但可以增强其后期强度。矿粉可以改善其流动度,随着矿粉的增加,注浆料的容重和膨胀率均呈下降趋势;矿粉对注浆料的28 d强度无显著影响,其早期强度随着矿粉的增加而下降,当S75矿粉掺量高于7%或S95矿粉掺量高于11%时,抗压抗折强度不满足规范要求。 相似文献
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15.
A new type of green reactive powder concrete (GRPC) with compressive strength of 200 MPa is prepared by utilizing composite mineral admixtures, natural fine aggregates, and short and fine steel fibers. The quasi-static mechanical properties (mechanical strength, toughness, fracture energy and interfacial bonding strength) of GRPC specimens, cured in three different types of regimes, are investigated. The experimental results show that the mechanical properties of the C200 GRPC made with the powder binders that is composed of 40% of Portland cement, 25% of ultra fine slag, 25% of ultra fine fly ash and 10% of silica fume are better than the others'. The corresponding compressive strength, flexural strength and fracture energy are more than 200 MPa, and 30 000 J/ m2 respectively. The dynamic tensile behavior of the C200 GRPC is also investigated through the split Hopkinson pressure bar (SHPB) according to the spalling phenomenon. The dynamic testing results demonstrate that strain rate has an important effect on the dynamic tensile behavior of GRPC. With the increase of strain rate, its peak stress and relevant strain increase. The GRPC exhibits an excellent strain ratio stiffening effect under the dynamic tensile load with high strain ratio, resulting in a significant change of the fracture pattern. 相似文献
16.
Preparation of high performance ceramic tiles using waste tile granules and ceramic polishing powder 总被引：1，自引：0，他引：1
This paper presents an innovative approach to reusing waste tile granules （TG） and ceramic polishing powder （PP） to produce high performance ceramic tiles. We studied formulations each with a TG mass fraction of 25.0% and a different PP mass fraction between 1.0% and 7.0%. The formulations included a small amount of borax additive of a mass fracton between 0.2% and 1.2%. The effects of these industrial by-products on compressive strength, water absorption and microstructure of the new ceramic tiles were investigated. The results indicate that the compressive strength decreases and water absorption increases when TG with a mass fraction of 25.0% are added. Improvement of the compressive strength may be achieved when TG （up to 25.0%） and PP （up to 2.0%） are both used at the same time. In particular, the compressive strength improvement can be maximized and water absorption reduced when a borax additive of up to 0.5% is used as a flux. Scanning electron microscopy reveals that a certain amount of fine PP granules and a high content of fluxing oxides from borax avail the formation of glassy phase that fills up the pores in the new ceramic tiles, resulting in a dense product with high compressive strength and low water absorption. 相似文献
17.
Calcium carbide slag, generated in the hydrolysis process of calcium carbide, is an potential carbon capture reagent because its main ingredient is Ca(OH)2. Calcium carbide slag, a by-product of a resin factory was used as carbon capture reagent. The change of pH and electrical conductivity (EC) of the calcium carbide slag slurry with different solid-to-liquid ratios, as well as the capture efficiency and dynamics under different temperatures and flow rates of CO2 were studied. The properties of solid were characterized with XRD, TG-DTA, SEM and FT-IR before and after capturing carbon. The results show that the change of pH and EC were greater with low solid-to-liquid ratio than that with high solid-to-liquid ratio. The analysis of XRD and SEM show that the content of CaCO3 increased significantly, which improved that Ca(OH)2 and free CaO were reacted with CO2. The results of TG-DTA and FT-IR show that the physicochemical properties and microstructure of the slag changed after capturing CO2 because of the increase of CaCO3 content. All the results mentioned above improve the feasibility of utilizing calcium carbide slag to capture CO2 and offer a practical way for carbon emission reduction and disposal of wasted calcium carbide slag. 相似文献
18.
Saline soil stabilization is being increasingly applied in foundation treatment engineering. Chloride saline soil obtained from sites and laboratory-made chloride soil (ZS) with various NaCl concentrations prepared artificially were stabilized using alkali-activated slag (AS). A series of unconfined compressive strength (UCS) tests, X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDXA), thermal gravity-differential thermal gravity (TG-DTG), and ion concentration tests were conducted to investigate the strength variation and mechanism of the AS-stabilized chloride saline soils. The results showed that NaCl has a significant influence on the strength of AS-stabilized chloride saline soil and the strength of AS-stabilized ZS (GZS) increases with increase of chloride content in soil samples. Friedel’s salt (Fs) and NaOH are generated by the reaction of NaCl and CaO·Al2O3 (CA) in the slag in the GZS. Fs can fill the pores in stabilized soil, and NaOH can promote calcium silicate hydrate (CSH) generation. These two effects combine to enhance the strength of GZS. The relationship between the rate of increase of 28-d UCS of AS-stabilized chloride saline soil and the chloride content in soil was obtained through regression analysis of the increase of UCS of GZS. 相似文献