{"id":1861,"date":"2022-03-11T15:02:09","date_gmt":"2022-03-11T15:02:09","guid":{"rendered":"https:\/\/mircement.com\/?p=1861"},"modified":"2024-08-21T10:17:53","modified_gmt":"2024-08-21T10:17:53","slug":"opc-cement-in-bangladesh","status":"publish","type":"post","link":"https:\/\/mircement.com\/blog\/opc-cement-in-bangladesh\/","title":{"rendered":"Ordinary Portland Cement (OPC) in Bangladesh: Things to Consider Before Purchase"},"content":{"rendered":"

A cement is a substance that binds together different materials by a combination of chemical reactions through hydration. Cement is a powdery substance that starts reacting after getting into contact with water. It is the primary \u201cglue\u201d that holds a structure upright. Cement is one of the essential construction materials globally and acts as an inseparable component in the construction of buildings, bridges, harbors, roads, etc. The demand for cement is constantly rising worldwide, making it the 2<\/span>nd<\/span> most consumed commodity in the world after water.<\/span><\/p>\n

There are different types of cement available in the market. Choosing the best type of cement in Bangladesh <\/span><\/a><\/span><\/span>allows your construction project to become more rigid and durable. Before making a purchasing decision, you should make sure the type of cement<\/span><\/span> you intend to purchase suits your requirements. There are two significant categories of cement for general construction purposes: 1) Ordinary Portland Cement or OPC and 2) Portland Pozzolana Cement or PPC.<\/span><\/p>\n

What is Ordinary Portland Cement<\/b><\/span><\/h2>\n

Ordinary Portland Cement<\/span><\/a><\/span> is one of the most widely used cement types globally. In Bangladesh, OPC is mainly used in construction works. The name of the cement originated in 1824 by Joseph Aspdin due to its similarity in color and quality found in Portland stone. Portland stone is a whitish-gray limestone on the island of Portland, Dorset. OPC can reach high compressive strength, making it a popular choice in large construction projects.<\/span><\/p>\n

Ingredients of Ordinary Portland Cement<\/b><\/span><\/h2>\n

OPC consists of two major categories of raw materials:<\/span><\/p>\n

    \n
  1. Argillaceous or silicates of alumina, which is used made of clay and shale<\/span><\/li>\n
  2. Calcium carbonate is deposited in limestone, chalk, and marl. It is commonly known as calcareous materials.<\/li>\n<\/ol>\n

    The raw materials are mixed by standard proportions of about two parts of calcareous materials to one part of argillaceous materials. The mixture is then crushed and ground in ball mills, which can be performed in both dry and wet conditions. It is then burnt in a rotary kiln at more than 1400 degrees Celsius. Newly produced clinkers are then cooled and passed on to ball mills to be added with a standard gypsum ratio. Then the whole mixture is grounded to achieve fineness according to the class of the product.<\/span><\/p>\n

    OPC can contain different ratios of various components. However, the ratios must be within a specific range to be recognized as OPC. The following chart shows the percentage of different materials in OPC.<\/span>\u00a0<\/span><\/p>\n\n\n\n\n\n\n\n\n\n
    Lime (CaO)<\/span><\/td>\n60 \u2013 67%<\/span><\/td>\n<\/tr>\n
    Silica (SiO<\/span>2<\/span>)<\/span><\/td>\n17 \u2013 25%<\/span><\/td>\n<\/tr>\n
    Alumina (Al<\/span>2<\/span>O<\/span>3<\/span>)<\/span><\/td>\n3 \u2013 8%<\/span><\/td>\n<\/tr>\n
    Iron Oxide (Fe<\/span>2<\/span>O<\/span>3<\/span>)<\/span><\/td>\n 0.5 \u2013 6%<\/span><\/td>\n<\/tr>\n
    Magnesia (MgO)<\/span><\/td>\n 0.1 \u2013 4%<\/span><\/td>\n<\/tr>\n
    Sulfur trioxide (SO<\/span>3<\/span>)<\/span><\/td>\n1 \u2013 3%<\/span><\/td>\n<\/tr>\n
    Soda and Potash (Na<\/span>2<\/span>O+K<\/span>2<\/span>O)<\/span><\/td>\n0.5 \u2013 1.3%<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    These constituents undergo chemical reactions to form the significant four compounds, also known as Bogue Compounds. These are commonly known as Tricalcium silicate (C3S), Dicalcium silicate (C2S), Tricalcium aluminate (C3A), and Tetracalcium aluminoferrite (C4AF). The proportions of these four compounds differ in specific ranges in OPC. The strength of cement mainly depends on the C3S and C2S. The setting time of cement depends on the C3A.<\/span><\/p>\n

    Things You Should Consider Before Purchasing Ordinary Portland Cement in Bangladesh<\/b><\/span><\/h2>\n

    It would be best to consider some critical OPC properties before purchasing them because these properties are responsible for the quality of the cement.<\/span><\/p>\n

    Fineness<\/b><\/h3>\n

    Fineness refers to the particle size of OPC, which directly contributes to the rate of hydration. Thus, responsible for the rate of strength gain. Smaller particles have more excellent surface area-to-volume ratios. You should purchase OPC with around 95% of the cement particles smaller than 45 microns with an average size of 15 microns.<\/span><\/p>\n

    Source:<\/span> Define Civil<\/span><\/a><\/span><\/em><\/p>\n

    Soundness<\/b><\/h3>\n

    This property refers to the ability of a hardened cement slab or pastes to retain its volume after setting. If the composite particles are not in standard ratios, the soundness of cement can affect the integrity of your structure.<\/span><\/p>\n

    Compressive Strength<\/b><\/h3>\n

    The compressive strength of cement can be tested with compression testing machines. Make sure your preferred cement brand provides certification of the compressive strength that it claims. OPC should gain compressive strength ranging between 33 \u2013 53 MPa at 28 days, 22 \u2013 27 MPa at seven days, and 16 \u2013 27 MPa at three days of curing after casting.<\/span><\/p>\n

    Setting Time<\/b><\/h3>\n

    Setting time may vary depending on the grade of OPC. However, 30 minutes should be regarded as a minimum setting time for the initial setting and a maximum period of 600 minutes as the maximum setting time.<\/span><\/p>\n

    Where Can You Use Ordinary Portland Cement?<\/b><\/span><\/h2>\n

    OPC is great for almost all kinds of construction work. Here is a list of use case scenarios for OPC:<\/span><\/p>\n