Building Technology 4 - Estimates Part 1: Concrete and Masonry PDF

Summary

These lecture notes cover estimates for concrete and masonry projects. It details types of concrete, mixing proportions, and estimating methods for concrete pipes and hollow blocks. Pop quizzes are included to test students' understanding.

Full Transcript

USTP DEPARTMENT OF ARCHITECTURE BUILDING TECHNOLOGY 4 ESTIMATES PART 1: CONCRETE AND MASONRY AR. KAREEN JANE ABIABI, UAP INSTRUCTOR PLAIN AND REINFORCED CONCRETE By definition, Plain Concrete is an artificial stone as a result of mixing cement, fine aggre...

USTP DEPARTMENT OF ARCHITECTURE BUILDING TECHNOLOGY 4 ESTIMATES PART 1: CONCRETE AND MASONRY AR. KAREEN JANE ABIABI, UAP INSTRUCTOR PLAIN AND REINFORCED CONCRETE By definition, Plain Concrete is an artificial stone as a result of mixing cement, fine aggregates, coarse aggregates and water. The conglomeration of these materials producing a solid mass is called plain concrete. Reinforced Concrete on the other hand, is a concrete with reinforcement properly embedded in such a manner that the two materials act together in resisting forces. DIFFERENT TYPES OF CONCRETE USED IN CONSTRUCTION 1 Ordinary Portland cement 4 Low Heat Portland Cement used for massive sections designed to reduce the heat of hydration 2 The Rapid Hardening Portland Cement preferred when high early strength concrete 5 Portland Pozzolan Cement A low hardening characteristic concrete is desired 3 Blast Furnace or Sulfate Cement used on concrete structures designed to 6 High Alumina Cement. Its chemical composition is different from that of resist chemical attack Portland cement for having predominant alumina oxide content of at least 32% by weight Sulfur Trioxide 4.4% Iron Oxide 4.4% Alumina 7.1% Name another obstacle you can help your audience overcome. Lime 57.5% Silica 22.1% MAIN COMPOSITION OF CONCRETE AGGREGATES Aggregates for concrete work are classified into two: COARSE AGGREGATE FINE AGGREGATE such as crushed stone, crushed gravel or natural such as crushed stone, crushed gravel, sand or gravel with particles retained on a 5 mm sieve natural sand with particles passing on a 5 mm sieve For coarse aggregate (gravel), the maximum nominal size varies from 40, 20, 14 or 10 mm diameter. The coarse aggregate should be small enough for the concrete mixture to flow smoothly around the reinforcement. This is referred to as workability of concrete. PRINCIPLES OF CONCRETE MIXING The purpose in mixing concrete is to select an optimum proportion of cement, water and aggregates, to produce a concrete mixture that will meet the following requirements: 1. Workability 3. Durability 2. Strength 4. Economy 1. FRESH CONCRETE SHALL BE WORKABLE. meaning, that concrete could freely flow around the The ACI reinforcements to fill all the voids inside the form. Requirements 2. HARDENED CONCRETE SHALL BE STRONG. for Concrete are it shall be strong enough to carry the design load. as follows: 3. HARDENED CONCRETE COULD WITHSTAND THE CONDITIONS TO WHICH IT IS EXPECTED TO PERFORM. 4. CONCRETE SHOULD BE ECONOMICALLY PRODUCED. Concrete Mixture may be classified as either: DESIGNED MIXTURE PRESCRIBED MIXTURE Where the contractor is responsible Where the designing engineer in establishing the mixture specify the mixture proportion. The proportion that will achieve the contractor's responsibility is only to required strength and workability as provide a properly mixed concrete specified in the plan. containing the right proportions as prescribed in the plan. 40kg 50 kg Sand Gravel Class Proportion CONCRETE Cement Bag Cement Bag (cu.) (cu.) PROPOTION AA 1 : 1 1/2 : 3 12 9.5 0.50 1 A 1:2:4 9 7 0.50 1 Proportioning concrete mixture is done in two different ways: by weight or by volume method. The most convenient way is by the volume B 1 : 2 1/2 : 5 7.5 6 0.50 1 method using the empty plastic bag of cement, or by a measuring box for sand and gravel. C 1 : 3: 6 6 5 0.50 1 40kg 50 kg Sand Gravel Class Proportion Cement Bag Cement Bag (cu.) (cu.) AA 1 : 1 1/2 : 3 12 9.5 0.50 1 POP QUIZ 1: A 1:2:4 9 7 0.50 1 B 1 : 2 1/2 : 5 7.5 6 0.50 1 C 1 : 3: 6 6 5 0.50 1 A proposed concrete pavement has a general dimension of 10cm thick, 3.00 meters wide and 5.00 meters long. Determine the quantity of cement in bags, sand and gravel in cubic meters required using class “C” mixture. Using the Class C mixture: How many bags are needed? How many cubic meters of sand are needed? How many cubic meters of gravel are needed? 40kg 50 kg Sand Gravel Class Proportion Cement Bag Cement Bag (cu.) (cu.) AA 1 : 1 1/2 : 3 12 9.5 0.50 1 ANSWER: A 1:2:4 9 7 0.50 1 B 1 : 2 1/2 : 5 7.5 6 0.50 1 C 1 : 3: 6 6 5 0.50 1 Volume = Thickness x Width x Length V = 0.10 x 3.00 x 5.00 V = 1.50 cubic meters Using 40kg Cement Class C mixture, multiply the volume by the corresponding values: Cement : 1.50 x 6.0 = 9.0 bags Sand : 1.50 x 0.50 = 0.75 cubic meters Gravel : 1.50 x 1.0 = 1.50 cubic meters POP QUIZ 2: 40kg 50 kg Sand Gravel Class Proportion Cement Bag Cement Bag (cu.) (cu.) AA 1 : 1 1/2 : 3 12 9.5 0.50 1 A 1:2:4 9 7 0.50 1 B 1 : 2 1/2 : 5 7.5 6 0.50 1 C 1 : 3: 6 6 5 0.50 1 A reinforced concrete square column is 5.00 meters long with a cross sectional dimensions of 0.30 x 0.30 meters. Determine the quantity of cement, sand and gravel using Class A concrete. POP QUIZ 2: 40kg 50 kg Sand Gravel Class Proportion Cement Bag Cement Bag (cu.) (cu.) AA 1 : 1 1/2 : 3 12 9.5 0.50 1 A 1:2:4 9 7 0.50 1 B 1 : 2 1/2 : 5 7.5 6 0.50 1 C 1 : 3: 6 6 5 0.50 1 Volume = Thickness x Width x Length V = 0.30 x 3.00 x 5.00 V = 0.45 cubic meters Using 40kg Cement Class A mixture, multiply the volume by the corresponding values: Cement : 0.45 x 9.0 = 4.05 = 5 bags Sand : 0.45 x 0.50 = 0.225 cubic meters Gravel : 0.45 x 1.0 = 0.45 cubic meters COLUMNS, FOOTINGS, BEAMS AND GIRDERS Structurally, post is always supported by slab called footing or foundation. Same as slab, the most efficient method of estimating will be the volume method. CONCRETE PIPE Concrete pipe is much in demand for small and medium drainage construction, The use of concrete pipe as drainage structure materially saves cost of forms, time and labor costs as well. ESTIMATING CONCRETE PIPES 1. Find the net volume of the concrete pipe. That is, by subtracting the volume occupied by the hole from the gross volume of the pipe. 1. Knowing the net volume of the concrete, refer to previous table, under 40 kg. cement and class of mixture specified, multiply by the net volume found for cement, sand and gravel. MASONRY Concrete Hollow Block is popularly known as CHB. It is classified as load bearing and non-bearing blocks. Load bearing blocks are those whose thickness ranges from 15 to 20 centimeters and are used to carry load aside from its own weight. Non-bearing blocks on the other hand, are blocks intended for walls, partitions, fences, dividers and the like carrying its own weight whose thickness ranges from 7 to 10 centimeters. The standard hollow block has three void cells and two half cells at both ends having a total of four. These hollow cells vary in sizes as there are different manufacturers using different types of mold. Hence, it is recommended that concrete hollow blocks with bigger cells be considered in estimating for a more realistic result. In this study, what we want to know is the quantity of the materials needed for a certain masonry work made of CHB. ESTIMATING MASONRY WORK Estimating the materials for masonry work using hollow blocks could be done in either of the following methods: 1. By Fundamental methods 2. By the Area methods SAMPLE PROBLEM A concrete hollow block wall has a general dimension of 3.00 meters high by 4.00 meters long. Determine the number of CHB required to construct the wall. SOLUTION 01 FUNDAMENTAL METHOD 1. Divide the height of the fence by the height of one block. 3.00 / 0.20 = 15 layers 2. Divide the length of the fence by the length of one block. 4.00 / 0.40 = 10 pieces 3. Multiply the result of step 1 by step 2 15 x 10 = 150 pieces SOLUTION 02 BY AREA METHOD Let us examine first how many pieces of CHB can cover up one square meter area. From the figure on the left, it appears that one square meter area requires 12.5 pieces of concrete hollow blocks. Therefore, by multiplying the entire area of the wall by 12.50, we find the total number of CHB required. Thus, Area of fence: 3.00 x 4.00 m = 12 square meters Multiply: 12.00 sqm x 12.50 = 150 pieces POP QUIZ 3: Find the number of CHB needed to construct the fence shown in the image on the left side. You have 5 minutes to answer the question. After the go signal, turn on your camera and show your answer. SOLUTION: Face 1: 9.80 x 2.60 = 25.48 sqm x 12.50 = 318.50 318.50 x 2 similar faces = 637 pieces Face 2: 5.00 x 2.60 = 13 sqm x 12.50 = 162.50 pieces Face 3: 2.10 x 2.60 = 5.46 sqm x 12.50 = 68.25 68.25 x 2 similar faces = 136.50 Total Number of CHB: 637 + 162.50 + 136.50 = 936 pieces CLASS ANNOUNCEMENTS F2F CLASSES: OCTOBER 4, 2024 Everyone is expected to be finished with Architectural Drawings and have already started with Structural Drawings for checking, MIDTERM EXAMS: TBA Students who have already done Electrical and Plumbing Drawings are encourage to Topic Coverage: have their works checked by tomorrow. You may now start writing your Specifications Specifications and Estimates, which Estimates (Concrete, Masonry, includes the format from the master file. Metal Reinforcement) You may have the soft copy checked before final printing. PDF Files of Classes will be posted on Midterm Plate Deadline: Midterm Exams Google Classroom USTP DEPARTMENT OF ARCHITECTURE BUILDING TECHNOLOGY 4 THANK YOU FOR LISTENING! ESTIMATES PART 1: CONCRETE AND MASONRY AR. KAREEN JANE ABIABI, UAP INSTRUCTOR

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