澳门混凝土结构设计规范探讨

对澳门混凝土设计规范和荷载规范中的混凝土、钢筋的材料特性等内容进行了探讨,并且对两种规范存在的差异指标进行了比较,指出了两者的优劣,同时举例说明了PKPM软件进行澳门工程设计时参数的设定方法,为同类工程提供了参考。     

高强钢焊接箱形柱受力性能研究(Ⅰ)：残余应力统一分布模型

现有高强钢焊接箱形截面残余应力分布模型仅适用于特定强度等级的高强钢,尚缺乏适用于不同强度等级高强钢的残余应力分布模型。为此,基于不同强度等级高强钢焊接箱形截面残余应力的已有试验,研究钢材的强度等级、板件厚度及宽厚比对残余应力分布和峰值的影响,提出不同强度等级高强钢焊接箱形截面的残余应力统一分布模型。该模型采用多重阶梯函数形状,适用于屈服强度460~960MPa的焊接箱形截面,且满足每个板件自平衡条件和对称性。将残余应力统一分布模型的形状、数值和已有试验结果进行对比,证明该模型的准确性。在基于纤维模型的极限承载力数值分析中,分别采用残余应力统一分布模型和已有分布模型计算高强钢焊接箱形柱的受压承载力,并将各自得到的极限承载力与已有试验结果进行对比。研究结果表明,采用残余应力统一分布模型后,不同等级高强钢焊接箱形柱的纤维模型计算能更准确地预测其极限承载力。残余应力统一分布模型可为不同等级高强钢焊接箱形柱的二阶非弹性分析提供参考。     

混凝土早期强度推算法及实用分析

本文对＂成熟度法＂、＂等温强度龄期曲线法＂及＂等效龄期法＂介绍了其实际应用方法。通过实例对比计算发现三者有很大差距，并对差距产生的原因进行了初步分析，对其今后的使用提供了参考数据。     

深基坑支护计算中土性参数选取的探讨

土压力的计算是深基坑支护结构设计的重要环节,但土性参数的选取却是至关重要的。本文重点讨论与支护结构设计密切相关的主要土性参数———土的抗剪强度指标c、值。     

减缩剂对混凝土干缩开裂的影响及其应用

从试验设备、步骤等，阐述了干缩试验的方法，对试验的原材料和配合比及其常规性能测定结果作了分析，并提出工程中应注意的几点问题，以利采用减缩剂抑制混凝土开裂收到良好效果。     

偶联剂对玻纤制品的强度的影响

介绍了偶联剂的作用和常用品种。通过用不同种类及不同用量的偶联剂进行试验对比,总结出偶联剂对热塑性塑料制品的强度的影响,以及偶联剂对直接纱的强度的影响,并得出结论：偶联剂1或5适用于增强热塑性塑料;直接纱配方中偶联剂用量在0．4％时,性价比较好。     

Quality dependence study on dimensions for plano-concave molded glass lenses

A comprehensive study was conducted to analyze the quality dependence of a plano-concave molded glass lens on its own dimensions, i.e. the effective diameter, sag ratio, and center thickness ratio. To achieve this goal, a thermal-displacement coupled finite element analysis was carried out on the whole molding process, in order to get the results of curve deviation, temperature gradient, and residual stress with sets of variations in these dimensions. Then Taguchi method, one approach for design of experiments, was incorporated to conduct sensitivity analysis on the simulation results to figure out the dominating sequence of these dimensions. The results show that the effective diameter is the most influential factor among these three dimensions. In addition, curve deviation is sensitively proportional to diameter and sag ratio, but decreases insignificantly with greater center thickness ratio. However, residual stress is distinctly proportional to diameter and center thickness ratio, but increases very slightly with greater sag ratio. Results also confirmed the consequential relationship between temperature gradient and residual stress. These discoveries are fundamentally meaningful in getting an overall understanding of the dimensions’ influence on the molded lens quality, thus will help make decision in choosing proper dimensions for optical design.     

Features of liquid hydrocarbon and biomarker maturity ratios during HTHP semi-open system pyrolysis of type II and III source rocks

In order to study the liquid hydrocarbon generated by laboratory pyrolysis and the biomarker maturity ratios in expelled oil with the increasing simulation temperature, the Hydrous semi-open system high temperature high pressure (HTHP) pyrolysis experiments was performed on Type II and III source rocks from 350°C to 540°C. The results showed that expelled oil yields in both samples have a trend of increased first and then decreased with the increasing temperature, while an opposite tendency occurred in the residual oil. The biomarker maturity ratios, such as ∑C_21?/∑C₂₂₊ ratio in n-alkanes, Pr/Ph ratio in isoprenoid alkenes, Ts/Tm in terpenes, and C₂₉ββ/(αα + ββ) ratios in steranes are all better indicators in terms of maturity in pyrolysis. However, the maturity biomarkers ratios interpreted by the mechanism of isomerization such as C₃₁-homohopanes 22S/(22S?+?22R) and ααα C₂₉-sterane 20S/(20S + 20R), which had already reached their equilibrium values, indicating that microbiological deterioration is one reason for the failure indicative function of αααC₂₉sterane20S/(20S + 20R) ratio. This research may also play an important role in the studies about the evolution of sedimentary organic matters in geology.     

Brandverhalten von Brettsperrholz

Fire behaviour of cross‐laminated timber Cross Laminated Timber (CLT) is currently used in modern timber structures for load‐bearing wall, floor or roof elements as a high quality, innovative and cost‐effective structural element. Careful planning and implementation ensures the safe use of CLT in buildings with increased fire protection requirements and in accordance with the requirements of building‐design standards (e. g. EN 1995‐1‐1 and EN 1995‐1‐2) [1, 2]. Worldwide, many fire tests with CLT have been per‐formed to investigate the influence of different cross‐sectional build‐ups and various adhesives on the fire resistance of CLT floor and wall elements. This paper gives an overview of the extensive investigations, main outcomes are summarized and recommendations on the fire design of CLT elements are given. The investigations show that an adequate data base exists to reliably describe the fire behavior of CLT.     

镀铜钢纤维表面改性及其耐腐蚀性能和黏结性能

为了改善镀铜钢纤维与水泥基体的黏结强度,用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(MPS)和γ-巯基丙基三甲氧基硅烷(MPTS)对镀铜钢纤维进行表面处理.采用红外光谱、扫描电子显微镜(SEM)、氯化钠溶液浸泡腐蚀试验和黏结强度测试来评价处理后镀铜钢纤维的性能.结果表明:MPTS与镀铜钢纤维表面发生了化学键合,提升了钢纤维表面粗糙度;经过MPS处理和MPTS/MPS组合处理的钢纤维腐蚀溶液的吸光度积分只有未处理组的91%和45%;经过MPS处理和MPTS/MPS组合处理的钢纤维从水泥基体中拔出时所做的功相对于未改性组分别提升了43%和224%,与水泥基体的黏结强度得到了相应提高.