Increasingly, the Construction Industry is being dramatically impacted globally by internal and external forces. These influences range from acute labor and skill shortages, demographic and urbanization shifts, as well as, the Industry’s conversion from analog-based processes to digital workflows. This presentation will overview ten significant trends which are uniquely affecting the Construction Industry, creating both new challenges and opportunities, while transforming the Construction Industry.
What happens when a building owner calls with leaks into a building they just finished? After verifying whether they want to file a lawsuit or not, the course of action is important. An investigation and preliminary testing are typically recommended to understand the original design and the quality and consistency of the construction. Design of remedial repairs and a pilot repair program followed by retesting to confirm results. How extensive are the failures and how invasive do the repairs need to be? Costs? What materials were used and were they compatible? Public perception and developer/owner reputation are important. The occupants have just moved in. Higher expectation of successful repairs. Can we involve the original design and construction team? These are just a few of the issues that need to be faced early in this process. One must communicate often and clearly with the owner and rest of the project team in order to manage expectations, costs and construction quality control.
Concrete placement and finishing defects raised by a member of the project team may indicate a greater (unobserved) structural concern, a long-term durability issue, or simply an aesthetic problem. Concrete defects can delay the project schedule, require costly investigation fees, and necessitate removal and replacement. This presentation is intended to tackle concrete placement and finishing defects faced by the concrete construction industry. Topics will include: cold joints, delaminations, dusting, honeycombing, form leakage, plastic shrinkage cracking, floor flatness/levelness, in addition to others. This presentation will discuss the causes of these concrete defects, techniques for evaluating various defects, and approaches for mitigating these problems. Attendees will be introduced to various evaluation methods (e.g., impact-echo, ultrasonic pulse velocity, ground penetrating radar, concrete coring, petrographic examination, etc.) and when their use is appropriate.
The Avalon Mall parking facility is a four level above grade structure, consisting of three suspended parking levels (approximately 7,750sq.m. each) and one on-grade parking level connected to the existing mall with a new pedestrian bridge. RJC was the structural engineer of record. During construction of the parking structure extensive cracking of the suspended parking garage slabs was noted at two of the 24 pours. RJC undertook a visual assessment of the parking slabs in question to determine the extent of the noted cracking and determined over 750lin.m. of cracks ranging in size from 0.5mm to 6.5mm in width. Following the visual assessment destructive testing of the concrete was undertaken to determine its in-situ properties as well as to understand the full extent of the cracking.
A follow-on presentation to the discussion of our evaluation of over 1500 tire and lube facilities across the United States that prescribed immediate repairs where necessary, reinforcement where deterioration reduced capacity below acceptable levels and coatings necessary to protect structural steel and structural concrete (i.e. our 2019 Philadelphia presentation). This will be an in-depth presentation of how repairs were specified for (3) specific types of structures. The (3) structure types are exposed structural concrete, composite metal deck and fully reinforced form deck slabs all supported by steel structures and reinforced concrete walls. Presentation will include before, during and completion photos of each project discussed. Again, touch on the evaluation processes to include demand to capacity ratios review, evaluation system and inspection form, triggers to determine when shoring is necessary, calculation of capacities per AISC 360, ACI 318, ACI 562 and local building codes.
The presentation, through case studies, talks about emergency response services for structural issues encountered during construction of new design projects. Among other examples is an eleven story precast parking structure. The contractor observed significant diagonal faulted cracking of L-beams (supporting double-tee sections) near bearing locations, few days after pouring topping slab. In addition, inverted-tee girders were observed to be supported on cracked corbels at other locations. A quick turn around was required to mitigate any immediate life safety hazard posed by the structural distresses and buy time for thorough investigation, non-destructive testing, analyses, and repair design. Another example is a seven story precast parking structure. The structure was under construction and reportedly erected out of plumb. Poor concrete placing practices and poor weld detailing led to widespread cracking in multiple structural elements throughout the structure...
The iconic construction hard hat, a symbol of pride for the construction worker, has changed very little in 50 years. Developments in the understanding of the causes and prevention of debilitating and often fatal head injuries is leading to a revolutionary change in the way we protect our people from head injuries on the jobsite. The classic hard hat is about to change forever. This presentation will focus on new technology available today to minimize the effects of falls and impacts to the head of the worker. We will also focus on new technologies, already in development, that can further provide protection from head injuries. Industry requirements (OSHA, ANSI) will be reviewed, and the application of worldwide standards (EN) will be discussed and applied to new helmet development and implementation.
Nondestructive testing is often used in conjunction with traditional methods to assess construction, material, or structural deficiencies in new construction. This presentation describes evaluation of unique delamination failures within below-grade, exterior walls of a new subway station. The walls were conventionally reinforced mass concrete cast against a soldier pile and lagging retention system. Shortly after construction, leakage at cracks and joints was observed and injection processes led to delamination of the interior surfaces. The assessment objectives were to determine the extent and cause of near-surface discontinuities and evaluate the structural integrity of the walls. Nondestructive testing included flaw detection using Impulse Response [structural mobility testing] and reinforcement locating using ground-penetrating radar. Sampling and petrographic examinations were conducted to correlate test results with distress conditions and evaluate the in-situ concrete.
Post-tensioned concrete is a strong and durable material for construction of exposed parking structures. These types of structures are also fire resistant, but they can be damaged depending upon the severity of the fire. The structure in this presentation suffered significant fire damage early in its construction. The presentation will cover the discovery and testing methods used to determine the extent of fire damage, and the design of the repairs that were instituted to restore strength and allow construction to continue.
In new construction, cracks can appear for variety of reasons: curing, temperature deviation, pressure from adjacent conditions, or settlement. This presentation will outline various types of cracking, how to plan to avoid them, and how to address them after concrete has been placed.
Due to improper design or implementation sometimes Part of the New projects are re-executed or repaired. Islamabad - Rawalpindi BRTS (Bus Rapid transit System) Consisted of 20 Stations Covering around 23 km path connecting twin cities. Each station Roof Consisted of ACP Sheets Fixed on Aluminum Frame with Steel supports. The joints of ACP sheets were filled by Silicon but improper materiel and workmanship caused leakage in joints. Total length of joints was over 400,000 RFT. Leakage was invariably from almost every area.
Construction errors such as the misplacement of reinforcing steel and modifications like the addition of openings traditionally required intrusive repair methods. The addition of structural steel support or enlargement of the concrete elements is often not aesthetically pleasing or practical and the cost and time impacts are onerous. FRP strengthening solutions are non-intrusive, practical, and can be implemented quickly without major impact on the other building trades. The presentation will guide the audience through the feasibility assessment of FRP strengthening and implementation of the strengthening solution. The roles of the various parties, including the Engineer of Record, the FRP Design Engineer, the General Contractor, the Structural Contractor, and the FRP Installer, will be illustrated. Photographs of completed repairs will be presented.
Dealing with water is always a challenge when constructing a new structure. Whether it is water infiltration that was expected, or water manages to circumvent pre-planned waterproofing methods, it can wreak havoc on the building and interfere with construction schedules. The term “belt and suspenders” is often used in waterproofing and there is a good reason for it. Water chooses the path of least resistance, and many times that path is not discovered until it is too late. There are many methods of water control that can be implemented before, during and after a structure is completed. This presentation will focus on water control methods for new construction that can be implemented during or after the construction process.
A significant percentage of repairs are performed during the course of constructing new structures. Once a construction anomaly or error occurs the first concerns are for life safety and schedule impact. A review of the steps necessary to successfully perform repairs and minimize impacts to the ongoing construction. Examples of challenging problems and the traditional and non-traditional solutions to these problems will be discussed.