本文以CeO 2 作为示踪核素,SiO 2 、Al2O 3 和CaO混合物作为模拟砂土,在流动Ar气保护下,通过电加热引发铝热剂（Al和Fe2O 3 物质的量比为2∶1）,利用自蔓延高温合成（SHS）技术制备模拟核废物砂土固化产物。通过同步热分析、显气孔率测试、密度分析、X射线衍射分析、扫描电镜等手段分析了固化产物的表面形貌、组成结构和热稳定性。结果表明:采用SHS技术固化砂土,固化产物为无定形玻璃相和陶瓷相的混合物,改变固化比和示踪剂含量对固化体相结构组成的影响较小,固化产物密度在2.3～2.9g/cm3之间,高温状态下示踪核素Ce参与固化反应,主要以CeAl11O18形式和Ce2SiO5形式存在,固化体在常温到600℃具有较好的热稳定性。

The low oxygen content SiC fibers were exposed in simulated aeroengine circumstance of 14 kPa kPa kPa at 1200 ℃ for 1-50 h. Performances and structure of the fibers were characterized by element analysis, XRD, SEM and tensile test. The results show that the fibers have higher oxygen content, thicker oxide layer, lower strength compared with the fibers treated in dry air. Cracks and α-SiO2 crystal are more likely to occur in silica layer. The steam in the simulated circumstance can accelerate oxidation and crack formation in silica film.

The corrosion behaviors of lnconel 601 alloy immersed in the borosilicate glass (MW glass) and in ZnO,Mn2O3 modified borosilicate glasses (MZMF glass) containing simulant nuclear waste at 1060 ℃ for 168 h and 336 h were studied.The surface morphology,chemical composition of elements and the change of phase structure of the corrosion interface between the alloy and glass were studied by means of scanning electron microscopy (SEM),energy disperse spectroscopy(EDS) and X-ray diffraction (XRD).The results show that the Cr2O3 layer is formed on the alloy surface,and the corrosion depth of the Inconel 601 in MW waste glass melt is about 10 μm greater than that in the MZMF glass melt.In the MW glass,the Cr2O3 layer between the alloy and glass is fragmented because of the reaction among MgO,Fe2O3 and Cr2O3,which forms the crystal phase MgCr2O4and FeCr2O4.After immersing in the MZMF waste glasses for long time,the Cr2O3 layer formed on the surface of the alloy shows a continuous uniform state,and a thin (B,O,Fe,Mn,Zn)-containing zigzag layer formed on the surface of the Cr2O3 layer may prevent Cr2O3 from reacting with MgO or other constituents,and slow down the corrosion rate of the Inconel 601 alloy.

Plutonium‐containing waste with characteristics of high 239 Pu content and difficult reuse must be immobilized as soon as possible before safe disposal .Glass and glass‐ceramics considered to be more excellent confinement matrices (simpler process , lower cost and higher productivity ) for immobilizing plutonium‐containing waste than ceramics were studied extensively and thoroughly including alkali borosilicate glass , lanthanide borosilicate glass ,iron phosphate glass and zirconolite ,pyrochlore or mona‐zite‐based glass‐ceramics .T heir chemical composition ,chemical durability and the con‐tent of plutonium or its surrogate were presented and discussed by contrast in this paper .It is believed that glass‐ceramics will be a good alternative for immobilizing most of plutonium‐containing waste through consistently investigating and applying .

以白云石粉为主要原料,矿渣、粉煤灰和偏高岭土为辅助原料,用改性水玻璃激发的方式,制备得到碱激发碳酸盐复合胶凝材料.通过正交试验,研究了水玻璃的模数(A)和固含量(B),水玻璃与固体粉料的比例(C,简称液固比),以及矿渣(D)、粉煤灰(E)和偏高岭土(F)在固体粉料中的质量分数,对碱激发碳酸盐复合胶凝材料的流动度、凝结时间和力学强度的影响.结果表明,B、C和F对流动度影响显著,B和C对凝结时间影响显著,6个因素对力学强度的影响比较复杂.制备得到的碱激发碳酸盐复合胶凝材料流动度较好,凝结时间适宜,早期强度可达到37.9MPa,绝热温升为31.8℃.和混合水泥相比,碱激发碳酸盐复合胶凝材料在某些领域更有优势得到应用.

It discussed about the reason of segregation of porous expanded perlite lightweight aggregate concrete,the segregation problem of the lightweight concrete has been resolved successfully by adding fly ash,high performance admixture and porous expansive perlite pre-wetting and other technical measures,the porous expanded perlite lightweight concrete CL5~CL10 was prepared with good workability and uniformity,no segregation,ease of casting and excavation.

Besides the conventional loads,the accidental loads should be considered on the safety design for the concrete filled steel tube(CFST),and one of accidental events is the lateral impact.According to the stress state of concrete and steel,the constitutive model of RHT is used for the concrete,and that of John-Cook is used for the steel.The damage evolution rules for the inner concrete are studied using the dynamic finite element software of AUTODYN,in the conditions of the impact varied with mass,velocity and the position contacted with CFST,and different restrained types at the ends.The results show the damage begins from the contact position between the impact and the CFST,and develops toward the bottom of an impact position and the restrained end.During the interaction between the impact and the CFST,the strong damage zones are also generated near the restrained end and the zone of maximum deflection.There is a strong damage zone in the upper concrete near the impact position;and the damage characteristics at the end are decided by the restrained type: the strong damage zone lies in the restrained region for the simple support end,and lies outer for the clamped support;the damage distribution in the maximal deflection is controlled by the relative position between the impact and the center of CFST and the restrained type at the end.The inner energy absorbed by concrete increases with velocity,the weight of impact,and the horizon distance between the impact position and the center of CFST.There is a larger plastic strain near the impact position,which may decrease the capacity of resist compression for the impacted CFST.The results are significant to assess the residual capacity of CFST suffered from the lateral impact.

A simulated radioactive sandy soil waste with the particle size of ≤200 μm was immobilized using anthanon Ce as a tracer element by a thermit self-propagating high temperature synthesis（SHS） process.The composition,the structure and the normalized release rate of the products with different Ce contents were characterized by scanning electron microscopy,measurement of density,X-ray diffraction,X-ray fluorescence analysis,inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectroscopy（ICP-AES）.The results show that the tracer element Ce mainly forms the crystalline phases CeAl11O18 and Ce2SiO5 when the amount of CeO2 is 1%（in mass）.The self-propagating high-temperature synthesis immobilization resulted in vit-reous products with the amorphous phase particles and crystallines dispersed in the matrix.The volume density was over 3.0 g/cm3.The normalized release rate of Ce during 28 d was 10-5-10-6 g/（m2？d）,which was lower than that of borosilicate glass.The normalized release rate of Ca,Si and Al during 28 d was 10-3 g/（m2？d） and the release rate of Fe was 10-4 g/（m2？d）.

研究了粉煤灰和偏高岭土2种掺合料对高贝利特水泥基本物理力学性能的影响规律,据此,配制得到工作性能良好,3d抗压强度大于12MPa,温升低于40℃的高贝利特水泥基低热灌浆材料,以适宜于大体积灌浆,提高灌浆材料的耐久性。

Rapid carbonation test and gas permeability radio method are used to study the durability of lightweight aggregate concrete. The concrete includes foam,lightweight aggregate，pre-wetting and air entraining. The test results show that The combined-effect of air entraining agent(AEA)and aggregate pre-wetting can increase permeability. The anti-carbonation capacity of pre-wetting and air entraining lightweight aggregate concrete is 40% greater than that of ordinary concrete.gas permeability radio of pre-wetting and air entraining lightweight aggregate concrete is half of that foam concrete and expanded pearlite concrete.

The immobilization of radioactive waste using self-propagating high-temperature synthesis processes is a new research direction.Solidification theories,status of solidification research and solidification characteristics of SHS immobilization are analyzed and discussed quite systematically.SHS immobilization has some merits,such as simply process,excellent energy utilization efficiency,low time consumption and low cost for facility construction.It can select the appropriate reaction system for different types of radioactive waste,and design for the composition of product.It can enable immobilization to be deployed directly at disposal sites or in situ.Simulating experiments are conducted for immobilization of two forms nuclear waste introduced by SHS method of thermite,one form is toxic materials under explosion,the other form is sandy soils contaminated with actinides.

The crack redistance of different content of Polyacrylonitrile Fiber Reinforced Mortar has been studied and the mechanism of anti-cracking has been analyzed.The results indicate that when content percentage of fiber is 0.5 kg/m~3,0.8 kg/m~3,and 1.0 kg/m~3,crack of mortar can reduce 32.7%,60.5%and 94.8%.

Various methods of sealing mould were investigated to solve the problem of poor sealing effect in concrete antipermeability tests.The results indicate that the cold type of sealing mould,which uses putty as sealing material to coat the concrete samples with some other complementary measures,is feasible to substitute for the hot type of sealing mould.The phenomena of water leakage between the mould and the concrete test block didn't come up until the hydraulic pressure of automatic pressurized concrete permeability meter was up to 2.5 MPa.

This paper mainly investigated the impermeability of cementitious capillary crystalline waterproof material by the impermeability test and microanalysis,and relative mechanisms of action have been discussed.The results show this cementitious capillary crystalline waterproof material has excellently continued capillary crystalline,void plugging and waterproof performances.