大面积耐磨地坪整体施工技术

江西江铜龙昌精密铜管有限公司成品库扩建工程混凝土地面设计为耐磨地坪,耐磨面层材料为金刚砂。地面施工中高标准严要求,从材料选取、配方到操作工艺、成品养护等进行全过程控制,严格执行了耐磨地坪整体施工技术,保证了工程质量。本文主要介绍了耐磨地坪的施工工艺及操作要点,并进行了经济效益分析。     

密实性耐酸混凝土在地坪地沟防腐工程中的应用

介绍了密实性耐酸混凝土的特性,以及在地坪、地沟中的防腐施工方法.     

密实性耐酸混凝土在地坪地沟防腐工程中的应用

介绍了密实性耐酸混凝土的特性，以及在地坪，地沟中的防腐施工方法。     

筏板基础大面积滑动层施工技术

介绍了采用大面积滑动层控制大体积混凝土裂缝的施工选材、施工要点、细部结构以及注意事项。     

大面积地下室无渗漏施工技术

如何保证大面积地下室无渗漏成为许多施工一线人员潜心钻研的课题,在此,笔者根据自己的实践经验,介绍了合肥包河万达广场大商业大面积地下室施工采用抗渗混凝土、留置后浇带、预埋遇水膨胀止水条及止水钢板的无渗漏施工技术.     

筏板基础大面积滑动层施工技术

介绍了采用大面积滑动层控制大体积混凝土裂缝的施工选材、施工要点、细部结构以及注意事项。     

焦化厂硫铵工段混凝土地坪的防腐

介绍了焦化厂硫胺工段混凝土地坪的防腐修补情况以乙烯基酯树脂为主材，效果较好。     

工业厂房地坪施工质量通病分析及防治

分析了地坪混凝土产生裂缝的物理、化学、力学原因，提出了沉降与裂缝控制的综合技措与对策。     

马钢2250mm热轧带钢土建工程关键部位的质量控制

通过对马钢2250热轧带钢土建工程监理实践的总结，提出超长、超深砼结构和重载地坪的质量关键部位，采取加密跟踪、科学计算等事前和事中控制措施，有效解决了主轧线定位、预埋件安装、砼结构裂缝、重载地坪处理和逆作法等施工质量难题，并为类似工程提供了可借鉴的方法。     

高层建筑现场混凝土施工质量综合控制管理措施

混凝土作为高层建筑用量最大的建筑工程材料,其施工质量直接关系到高层建筑的整体质量,因此,必须加强高层建筑现场混凝土施工的管理。本文首先概述了高层建筑混凝土施工质量的影响因素,进而从具体方面论述混凝土施工质量管理措施,可以为高层建筑混凝土施工管理提供合理的参考。     

Investigation of Settlement of a Jointed Concrete Pavement

A section of jointed concrete pavement on U.S. 75, which was built from 1982 to 1985, in the Paris District of the Texas Department of Transportation (TxDOT) experienced severe pumping and settlement, even though two types of treatment (full depth repair and polyurethane foam injection) were performed. An extensive field investigation was conducted using ground penetrating radar, falling weight deflectometer, dynamic cone penetrometer, and coring to identify the causes of the continued pumping and settlement problems, and develop an optimal repair strategy. The pavement evaluation included tie bar condition, load transfer efficiency (LTE) at transverse and longitudinal construction joints, and base support conditions. Some of the tie bars failed in shear due to corrosion, which resulted in substantially low LTEs (<40%) at longitudinal construction joints. Pumping and settlement problems were more pronounced where the tie bars failed; the resulting large deflections exacerbated the pumping and settlement problems. The results demonstrate the importance of adequate LTEs (>80%) provided by tie bars, base and subgrade support, in providing satisfactory JCP performance. Inadequate design or construction of any of these critical elements could lead to performance problems, potentially including severe settlement, which is quite difficult to repair. To repair this pavement section, the Paris District of TxDOT is planning to retrofit tie bars by the “slot stitching” method, along with filling the voids under the slab using grout, followed by thin overlay using latex modified concrete to correct the differential elevation problems at longitudinal construction joints. It is expected that this repair strategy will address the distress problems and extend the pavement life.     

露天采坑做尾矿库时防渗工程的施工措施

介绍大岭矿露天采矿结束后,为实现露天采坑做尾矿库并保证地下矿正常开采,对露天坑防渗加固时针对边坡脱落、坡面不平、坡度大以及施工范围大、体量大、混凝土输送距离长等具体情况,采取的边坡整形,混凝土泵送、浇筑,土工膜铺设和保护层施工等措施。     

Inspecting the Lightweight Precast Concrete Panels in the Woodrow Wilson Bridge Deck of 1982

This paper presents the results of a detailed inspection of the deck panels of the Woodrow Wilson Bridge installed in 1982. The original cast-in-place concrete deck, constructed in 1962, was replaced with full-depth lightweight precast concrete deck panels that enabled rapid construction with minimal traffic disruption. The inspection of the Woodrow Wilson deck provides valuable information about the performance of the precast concrete panels, joints, and connections after 20 years of very harsh traffic loads and environmental stressors. The deck panels performed well overall, with the only serious problems at expansion and contraction joints. All of these joints exhibited cracking and rusting. The most prevalent type of cracking appeared to be due to restrained shrinkage between the new polymer concrete, the older precast panels, and the rigid steel joints. This location is more vulnerable to cracking and leaking because there is no prestress across the joint. The multilayered corrosion protection methods used for the transverse and longitudinal post-tensioning tendons were very successful.     

广州百货大厦新翼商业楼的钢管混凝土施工技术

广州百货大厦新翼商业楼采用逆作法施工,利用大量钢管柱、钢构架柱和高强混凝土C60作为结构承重构件,在钢结构施工中主要对构件加工、构件进场和运输、现场吊装、钢构件的焊接、构件安装等施工工艺进行质量控制,高强混凝土施工中主要对吊装加固、混凝土制作、现场浇灌等施工工艺进行质量控制,适应了逆作法施工中对上下承重结构的要求,解决了大跨度和某些特殊结构的需要,减轻了结构重量,加快了工期;在减少柱截面同时大幅度提高了混凝土的承载能力,增大了商场使用面积,取得了良好的经济效果。     

筏板基础大体积混凝土施工防裂措施

通过炼钢转炉基础筏板大体积混凝土施工,介绍了大型设备的基础大体积混凝土的施工技术,分析了大体积混凝土产生裂缝的主要原因,提出了防止混凝土温度裂缝的主要技术措施和控制方法.     

Use of an Infrared Joint Heater to Improve Longitudinal Joint Performance in Hot Mix Asphalt Pavements

Longitudinal joint cracking is one of the most prevalent forms of distress in asphalt concrete pavements. The joint area does not achieve the same density as the mat due to an unconfined edge on the initial pass and a cold joint during the second pass. The lower density allows water to penetrate and the material cracks, usually within one?year of construction. There are many techniques for constructing longitudinal joints, one being to preheat the joint prior to paving the second lane. This paper describes a field study conducted in New Hampshire using an infrared joint heater. Thermocouples were embedded in the pavement to determine the extent of heat penetration from the infrared heaters. Cores were taken along the joint and in the travel lanes for both the control and test sections. Density and strength measurements were taken on the cores. Permeability measurements along the control and test joints were performed. A cracking survey performed one?year after construction showed that the section of pavement where the infrared heater was used had significantly less cracking than the control section.     

Seismic Performance of Concrete-Filled FRP Tube Columns for Bridge Substructure

A set of column-footing subassemblies were prepared to investigate construction feasibility and seismic performance of structural joints for concrete-filled fiber reinforced polymer (FRP) tubes (CFFT) as bridge substructure. Based on the common practices of the precast industry and previous research on CFFT, the test matrix included a control reinforced concrete (RC) column and three CFFT columns, all with similar RC footings. The three CFFT columns included a cast-in-place CFFT column with starter bars, a precast CFFT column with grouted starter bars, and a precast CFFT column with unbonded posttensioned rods. The columns were subjected to a constant axial load and a pseudostatic lateral load. All proposed joints proved feasible in construction and robust under extreme load conditions. FRP tube, when secured properly in the footing, showed great influence on the seismic performance of the column by providing both longitudinal reinforcement and hoop confinement to the core concrete. The CFFT columns exhibited significant improvement over traditional RC columns in both ultimate strength and ductility. The study also showed that practices of the precast concrete industry can be easily and effectively implemented for the CFFT column construction.     

商住楼大体积混凝土筏板基础施工技术

介绍深圳市宝安福永时代景苑商住楼大体积混凝土筏板基础工程的施工过程，通过运用配合比设计，改善地基的约束条件，降排水处理，控制混凝土入模温度，混凝土表面处理和养护等方面的综合技术措施，较成功地保证了施工质量．     

大钢模板施工技术在高层建筑中的应用

文章通过大钢模板施工技术在高层建筑剪力墙施工中的应用实例,介绍了大钢模板的设计、施工工艺及使用效果,为高层建筑中清水砼剪力墙的施工提供了成功的经验。     

Ground Displacements from a Pipe-Bursting Experiment in Well-Graded Sand and Gravel

Pipe bursting is a construction technique that involves the replacement of an existing buried pipe with potentially much less surface disturbance than traditional cut and cover construction. However, excessive ground movements associated with pipe-bursting operations may lead to damage to surrounding infrastructure. A static pipe-bursting experiment was performed in sand and gravel within an 8-m-long, 8-m-wide, and 3-m-deep test pit to quantify the ground displacements from pipe bursting. An existing unreinforced concrete pipe buried 1.385 m below the ground surface was replaced with a high-density polyethylene pipe. Pulling force and the three-dimensional nature of surface displacements associated with pipe bursting are examined. The 4-m wide surface response had a peak vertical displacement of 6 mm. In addition, transverse displacements of 1.2 mm resulted in the formation of a tension crack in the ground above the concrete pipe. This experiment offers data that improves the understanding of the mechanisms of ground disturbance, and provides unique experimental data for calibration of numerical models.