QAQC in Construction

1. Drying Shrinkage Concrete by nature is a porous material. This means that when it is curing, the water in the concrete takes up space. As concrete hardens, it loses its moisture through evaporation resulting in empty capillary pores and a slightly smaller shape. This process is known as drying shrinkage. Since concrete is very rigid, this shrinkage causes an increase in tensile stress, which may lead to, cracking, internal warping, or external deflection. Concrete cracks when the drying shrinkage stresses exceed the tensile strength of the concrete. The spacing and size of cracks depend on the amount of shrinkage, degree of restraint, and amount and type of reinforcement. Drying shrinkage is the number one reason for cracks in concrete. 2. Lack of / improper use of control joints Control joints are most commonly installed in slab-on-grade concrete that is used in places such as driveways, pavements, house slabs, basement floors, and industrial spaces.  Control joints are general...

  Procurement management follows a logical order. First, you plan what you need to contract; then you plan how you’ll do it. Next, you send out your contract requirements to sellers. They bid for the chance to work with you. You pick the best one, and then you sign the contract with them. Once the work begins, you monitor it to make sure that the contract is being followed. When the work is done, you close out the contract and fill out all the paperwork. You need to start with a plan for the whole project. Before doing anything else, you need to think about all of the work that you will contract out for your project. You will want to plan for any purchases and acquisitions. Here’s where you take a close look at your needs to be sure that contracting is necessary. You figure out what kinds of contracts make sense for your project, and you try to define all of the parts of the project that will be contracted out. Contract planning is where you plan out each individual contr...

  Soil compaction is an operation common to most construction projects and increases the strength and stability of soils to support earthworks, structures, and pavements. Techniques to achieve maximum soil density are well known, and the outcomes can be tested and quantified using standard methods. Soil material is placed in layers, or lifts, in depths from a few inches to a foot or more, and compaction equipment rolls, kneads, vibrates, or sometimes uses dead-weight to consolidate the soil. The Right Kind of Compaction Test Specifications for soil compaction are established during the design phase of the project and depend on both total loads anticipated and whether those loads will be static or dynamic. Judging the adequacy of compaction efforts using qualitative measurements like penetration resistance or observation of wheel traffic is not sufficient to determine if the specifications have been met. Standard Proctor specifications (ASTM  D698  / AASHTO  T 99 ) wo...