The Influence of the Physico-Chemical Properties of Water on the Compressive Strength of Concrete

Abstract

Objective: To determine the influence of the physico-chemical compositions of the different sources of water on the compressive strength of concrete.
 Materials and Methods: Seventy-two 150mm x 150mm concrete specimen were cast using six different sources of water and cured using the same water sources by immersion for 7, 14, 21 and 28 days. Each water sample was used to produce 12 specimen, three each for the four different ages. Concrete cubes were weighed using digital weighing machine before testing. Test for compressive strength was done using digital compressive test machine after which the Average Compressive Strength (ACS) of the three samples was determined.
 Results: The silt content of the fine aggregates used was within the recommended percentage specified by the IS part II 1963. The results obtained from the slump test classifies the concrete produced for the study as stiff or extremely dry. Though the Amissano and Aquarium water recorded some amount of slump, their slumps could still be described as no-slump and cannot be classified. The figures for the compacting factor test indicated low workability for the concrete produced for the test. It was only the concrete produced from the Kakum river water that had a medium workability. The sea water recorded the highest pH and was followed by the Kakumdo well water. The least pH was recorded by the Amissano well water. The total dissolved solid (TDS) of the Kakumdo well water and the sea water were far higher than the Ghana standards. On the other hand, the figures recorded by the Kakum water for chloride, total hardness, calcium hardness, magnesium hardness and electric conductivity were below what is prescribed by the Ghana Water Company Limited (GWCL). The calcium hardness of the Kakumdo well water was (160mg/l) more than the standard. The Amissano well water specimen recorded the least ACS both at age 7 and 28. This was the lowest among all the samples produced from the various sources of water used for the experiment. The significant strength increase of the Amissano well water samples was recorded at age 14 and 21. The Kakumdo water specimen recorded the highest earliest strength of 20.339KN/mm2 and was followed by the Kakum river water. The samples from this source still recorded the highest at age 14 and 21. But at 28, it was overtaken by the Kakum river water samples with the Kakum river samples recording 26.439 KN/mm2 as against the 25.484 KN/mm2 registered by the Kakumdo well water samples. The Aquarium well water specimen recorded high strength at both age 7 and 28 than the Amissano well water specimen.
 Conclusion:
 The Aquarium water and Amissano well water were more acidic, meaning their pHs were lower than 6. This had significant influence on the ACS of the samples produced from them. This was evident in the case of the Amissano well water samples which recorded the lowest earliest strength of (12.173N/) among the six sources. The ACS difference recorded between the Aquarium and Amissano well water samples which were all acidic was 5.379KN/mm2. This means that higher the acidity of the water use for the production of concrete, the lower the ACS. The Amissano well water was 10 times more acidic than the Aquarium water and 20 times higher than the Kakum river water, pipe borne water and Kakumdo well water but 40 times higher than the sea water.

Bestmittel and Silica Fume Effect on Concrete Compressive Strength With Seawater Curing

“…The pH of seawater used for curing concrete test specimens was also 8.56. It is essential to measure the pH of seawater before the curing process (Akomah & Jackson, 2018;Al Jaaf et al, 2019), as shown in Figure 3.…”

Review article: Atmospheric Pressure, Water with Air, Porosity and Strength of Concrete (In memory of Professor László A Gömze)

“…In recent years, the attention of researchers has been drawn to the fact that the properties and quality of various materials can be determined not only by the quality of chemicals, but also by their physical and chemical properties [16]. In addition, in area of pharmacy it was shown that the quality of the final product (drug in this case) obtained as a result of local interaction of different starting materials depends not only on the quality of the main materials, but also on the physical and chemical properties of materials and substances that play the role of fillers, previously considered chemically inert [17][18][19].…”

“…Despite the fact that the quality of the water used is determined by the relevant standards, the list of controlled physico-chemical indicators of the quality of water used for hydration of cement in the production of concrete is not fully defined. There is no division of water into groups that differ in indicators of key physical and chemical properties [2,3,16]. This is paradoxical, but the influence of the physical and chemical properties of water involved in the process of hydration of cement on the strength of concrete has not been fully studied.…”