## why a maximum water cement ratio spec concrete

## Why 0.35 w/c for 4000-psi concrete? Concrete Construction ...

01/07/1997 When pricing concrete, our salespeople have a problem with projects for which there are conflicting specification requirements. Some engineers and architects in our area specify both compressive strength and maximum water-cement ratio, but the water-cement ratios are ridiculously low for the strength given. For instance, for a 4000-psi 28-day strength, the maximum water-cement ratio

Get Price## Understanding Minimum Specified Compressive Strength ( f c

maximum water cement ratio of 0.45. A concrete subcontractor submits the project specifications to the Ready Mix Concrete producer. These requirements forces concrete producers to use equations; f’ cr = f’ c + 1.34s (for mixes with 30 or more test data) or f’ cr = f’ c – 1200 (for mixes with no test data history) Where f’ cr is the average compressive strength If f’ c is 4500 psi ...

Get Price## Concrete Specifications – Why Water Cement Ratio: Why Not ...

The water-cement ratio (more correctly water-cementitious ratio) is a criterion for concrete that is very important and governs many of its desirable properties to include porosity, permeability, freezing/thawing resistance, and strength, just to name a few. So it’s not unexpected that specifications may call for a limit on the maximum water-cementitious ratio (w/cm). But when is a maximum w ...

Get Price## Water-Cement Ratio in Concrete - a detailed description

Water-cement ratio = weight of water/weight of cement According to The American Concrete Institute (ACI) 318 and ACI 332, the maximum water-cement ratio is specified is 0.45. According to Uniform Building Code 1997, the maximum water-cement ratio is 0.50 if the concrete is exposed to freezing and thawing in a moist condition or to de-icing chemicals.

Get Price## Concrete Durability Specification by Water/Cement or ...

01/05/1994 Previous work has suggested that, although water-cement ratio may be the most suitable specification parameter within a single cement type, strength should also be specified if comparable concrete durability is to be achieved with a range of cement types. To test this proposition, two series of concrete mixes were prepared with a variety of cements, including slag, fly ash, and limestone ...

Get Price## What is Water Cement Ratio? - Guide Calculation – Civilology

Calculation of Water Quantity for Concrete. As you can see from the Chart, the W/C Ratio varies from 0.4 to 0.7 depending on exposure conditions. If we need to calculate Water quantity for concrete, first find the cement content for the volume. Therefore, Required amount of water = 0.5 X 50 kg = 25 litres / 50 kg cement bag.

Get Price## Importance of Water Cement Ratio in Concrete Countertop ...

The water to cement ratio largely determines the strength and durability of the concrete when it is cured properly. The w/c ratio refers to the ratio of the weights of water and cement used in the concrete mix. A w/c ratio of 0.4 means that for every 100 lbs of cement used in the concrete, 40 lbs of water is added. Typical Water-Cement Ratios in Concrete Mixes. Typical w/c ratios are as ...

Get Price## Importance of Water-Cement Ratio in Concrete

14/11/2018 Water-Cement Ratio is defined as the ratio of the weight of water to the weight of cement. Water/cement ratio as per IS 10262 (2009) for the concrete mix varies from 0.4 to 0.6. 0.7 w/c ratio is also used for pumped concrete. 0.5 w/c ratio indicates, that for every 100 kg of cement, 50 lit. of water

Get Price## Water-Cement Ratio Concrete Construction Magazine

19/03/2018 Why a Maximum Water/Cement Ratio Spec? ... If we fog spray flatwork to help prevent shrinkage cracking, is there any danger of increasing the water-cement ratio at the surface and reducing the strength of the concrete? More. Tags: Concrete Strength, Water-Cement Ratio, Cracking and Crazing. Posted on June 01, 2011. Durable, Decorative Concrete By Joe Nasvik. High durability concrete

Get Price## Water Cement Ratio Watercement Ratio Water Cement ...

11/01/2020 With the proper water-cement ratio concrete becomes more durability, porosity, and color will be balanced. Recommended Water cement ratio for concrete, For ordinary concrete work (sidewalks and driveways): 0.6 to 0.7; If required higher quality concrete is desired: 0.4; The practical best water-cement ratio is from about 0.40 to over 0.60. A ratio of 0.3 is made concrete too stiff

Get Price## Concrete Mix Ratio and How to Mix Concrete Including a ...

In an ideal world, where everything is delivered dry, a water to cement ratio of approximately 0.55 should be used. As we have explained above, if requiring 25kg of cement in your mix, then to calulate the suggested volume of water it would be: 25 x 0.55 = 13.75kg (litres) of water. Note: This is the maximum amount of water that should be used.

Get Price## 3.1.6 Concrete specification - NHBC Standards 2021 NHBC ...

03/01/2017 correct control of the water:cement ratio; full compaction of the placed concrete; good curing. Concrete in non-hazardous conditions Table 4: Minimum specifications for general purpose concrete mixes. Location and use BS 8500 and BS EN 206; Ready-mixed concrete (designated mix) Site-mixed concrete (standardised prescribed mix) Consistence class: Substructure and ground

Get Price## DESIGNED CONCRETE SPECIFICATIONS - The Constructor

If a specification for designed concrete is to be complied correctly the following details need to be included: A requirement to conform to BS 5328, or BS EN 206-1 and BS 8500-2. The compressive strength class. The limiting values of composition e.g. maximum free water/cement ratio, minimum cement content or the deign chemical class where ...

Get Price## What is the effect of water to cement ratio on the ...

Attached please find the W/C vs concrete strength graph. Figure shows that validity range of water to cement ratio is very limited. Compressive strength is at peak, when water to cement ratio is low.

Get Price## Why a Maximum Water/Cement Ratio Spec? Concrete ...

16/01/2018 Question: I’m bidding on a project that has a 4000 psi design strength specification and a maximum 0.45 water/cementitious materials ratio (w/cm) requirement.I can produce 4000 psi at a much higher w/cm than 0.45, so why

Get Price## Is a 0.44 Water-Cement Ratio ... - Concrete Construction

01/10/1997 But a water-cement ratio as low as 0.44 is seldom needed for foundation concrete. ACI 318-95, Building Code Requirements for Structural Concrete, requires a maximum water-cementitious materials ratio of 0.45 for concrete exposed to freezing and thawing in a moist condition, deicing chemicals or high sulfate levels.

Get Price## Specification - Concrete Structures Eurocode - Eurocode ...

14/07/2021 Cement content should not be less than 325 kg/m3. Cement contents above 360 kg/m3 are unlikely to enhance abrasion resistance and excessive cement content can impair the power finishing process. Water/cement ratio. Water/cement ratio is of great importance. It should not exceed 0.55. Reducing to 0.50 is likely to increase abrasion resistance ...

Get Price## Water/Cement Ratio - an overview ScienceDirect Topics

The water-cement ratio of the tested standard mix proportion may be not appropriate and the strength of concrete may not accord with requirements, so the concrete strength should be rechecked. Three different mixture ratios will be adopted in rechecking. One is the standard ratio, and the other two are the ratios whose water-cement ratios are increased and reduced by 0.05 respectively. The ...

Get Price## MINIMUM AND MAXMUM CEMENT CONTENT Ref: SP:23

water-cement ratio and larger maximum size aggregate’. Recommendations for making durable concrete in various codes of practices envisage limits for maximum water-cement ratio, minimum cement content, cover thickness, type of cement and amount of chlorides and sulphates in concrete, etc. All these recommendations taken together tend to result in concrete being dense, workable,

Get Price## Concrete Cover Specifications for Reinforcement in ...

Concrete Cover Specifications as per European Code The euro code provides exact recommendation and details regarding the thickness of concrete cover. The code specified minimum concrete cover along with water to cement ratio, concrete strength, and minimum cement content based on the type of weather condition to which the structure is exposed. This can be clearly observed in Table-2 that ...

Get Price## How to Calculate Water Cement Ratio - The Concrete Network

08/05/2020 Use a maximum .50 water to cement ratio when concrete is exposed to freezing and thawing in a moist condition or to deicing chemicals per the 1997 Uniform Building Code. (Table 19-A-2) Use a maximum .45 water to cement ratio for concrete with severe or very severe sulfate conditions per the 1997 Uniform Building Code (Table 19-A-4) Water permeability increases exponentially when concrete

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