Thirdly writer , using linear elastic theory and finite element program ( ansys ) , analyzed expanding bolt pullout test . fifthly , writer using the modified mohr - coulomb failure theory , on the base of curving failure surface , derived a theoretical formula between pullout force and compressive strength . then the thesis compared the formula with the strength - detecting formula of expanding bolt pullout method 本文采用ansys有限元程序对胀栓拔出法试验过程进行弹性理论分析；以修正的摩尔-库仑破坏准则，在拟合实际破坏面的基础上推导出极限状态下胀栓拔出法的混凝土拔出力与混凝土抗压强度的理论公式，并把该公式与胀栓拔出法测强公式进行了比较。
Thea , aimed at different situation and with the combination of the compatibility truss theory and limited balance principle and the truss - strut model , the shear strengthening theoretic formula for the beams under concentrated load is put forward . ground on the test data and real engineering , the simple design formula is afforded 然后，作者以桁架一拱模型和软化桁架理论为基础，综合极限平衡原理，考虑了拉应变存在条件下混凝土抗压强度的软化，针对不同加固情况推导了集中荷载作用下的矩形截面约束梁的抗剪加固理论公式。
Specimens ’ cracking load under dead - load , fatigue failure characteristic , fatigue life , deflection of span - centre , fatigue flexural rigidity , maximal crack width , development of cracks and strain of concrete and steel bars have been investigated . the influence of fatigue cycle characteristic , ratio of reinforcement , kinds of aggregate and concrete compressive strength on the specimens ’ fatigue behavior has been also investigated 对试件的静载下开裂荷载、疲劳破坏特征、疲劳寿命、疲劳荷载作用下的跨中挠度、截面疲劳抗弯刚度、裂缝开展情况及最大裂缝宽度、钢筋及混凝土在循环荷载作用下应变等内容进行了研究,分析了疲劳循环特征值、纵筋配筋率、骨料种类、混凝土抗压强度等因素对试件疲劳性能的影响。
By orthogonal tests , the influence of water cement ratio , unit water and sand ratio on the compressive strength and the workability of recycled aggregate concrete is analyzed , water cement ratio is most main factor and a reasonable sand ratio 0 . 35 0 . 40 exists 采用正交试验分析了水灰比、单位用水量和砂率对再生混凝土抗压强度与拌合物和易性的影响,得出水灰比是影响再生混凝土抗压强度与拌合物和易性的最主要因素,存在一个合理砂率在0 . 35 0 . 40之间,对再生混凝土抗压强度和拌合物和易性最为有利。
2 . the research results indicate that the physical mechanical properties of hbc concrete such as compressive strength , flexural strength , splitting tensile strength , elasticity modulus and etc . is equivalent to that of opc concrete at age of 28d and remarkably surpasses opc concrete at 90d though its early age strength ( 3d , 7d ) is relatively lower . moreover , the relation of w / c ratio of hbc with compressive strength as well as strength at 7d with 28d ( c50 - c80 ) has been established and the effect of the dosage and type of fly ash on compressive strength of hbc has also been studied 研究了高贝利特水泥高性能混凝土的抗压、抗折、劈拉、弹性模量等一系列物理力学性能，结果表明，和opc混凝土相比， hbc混凝土早期( 3d 、 7d )抗压强度、抗折强度、劈拉强度、弹性模量较低，但随着龄期的增加， hbc混凝土28d诸项强度基本与之持平， 90d则全面超过opc混凝土；探讨了高贝利特水泥高性能混凝土水胶比与28d抗压强度的关系以及c50 c80强度范围内高贝利特水泥高性能混凝土7d强度与28d强度的关系；此外，对粉煤灰掺量及品种对高贝利特水泥高性能混凝土抗压强度的影响也进行了研究。
Sodium sulfate can decrease the compressive strength of concrete but increase the flexural strength . sodium nitrite can decrease the compressive strength of concrete but increase the flexural strength obviously . calcium nitrite can increase the compressive strength of concrete and decrease the flexural strength 掺入na2so4后混凝土的抗压强度降低但抗折强度有所提高;掺入nano2后混凝土抗压强度降低但抗折强度有很大提高;掺入ca ( no2 ) 2后混凝土抗压强度基本不变但同时也降低了抗折强度;而掺入nacl后混凝土抗压强度有所降低,抗折强度稍有提高。
Practices show that the compressive strength , the modulus of elasticity , the permeability coefficient and the compactness of concrete obtained respectively by the compaction method , the unconfined compression static compaction method , the sand trenching and filling method , and nuclear densimeters meet the requirement of design , and the mixing proportion of concrete of the side - wall is reasonable 实践证明施工中用击实法、无侧限抗压静力压实法、挖坑灌砂法及核子密度仪分别检测出的边墙混凝土抗压强度、弹性模量、渗透系数和密实度值均满足设计要求，边墙混凝土配合比合理。
Firstly , in the thesis writer studied and gained each test parameter of expanding bolt pullout method , and by using test data , writer regressed and gained the strength - detecting formula of expanding bolt pullout method . at the same time , the compositive strength - detecting formulas of expanding bolt pullout method , rebound method , ultrasonic method were gained . secondly , writer compared expanding bolt pullout method with them 本文研究确定了胀栓拔出法的各种试验参数；对试验数据进行系统的回归分析，得出胀栓拔出法的测强公式及与回弹法、超声法综合测强公式，并对这几个测强公式进行了精确性比较，发现胀栓拔出法的混凝土拔出力与混凝土抗压强度具有良好的相关关系。
Concrete compression strength was predicted by artificial neural network ( ann ) considered three factors , such as temperature , standing time and cooling and curing process after cool . also it was predicted in different rebound and ultrasonic values . fire resisting performance of concrete was studied and predicted 通过人工神经网络( ann )方法预测了火灾后考虑不同受火温度、静置时间、冷却及冷却后的养护方式三种影响因素的混凝土抗压强度；预测了火灾后考虑不同回弹值、大连理工大学博士学位论文一超声波速值等因素的混凝上抗压强度，研究并预测了火灾后混凝土的抗火性能。
