So it can be permeable and non absorbent at the same time. But it seems that acrylic ground is formulated to be moderately absorbent to help make a mechanical bond with the oil. As Ron says, make sure you put on at least 3 coats of acrylic ground when painting on board or canvas and using oils because acrylic ground is somewhat absorbent.
I would not worry about oil soaking through a few coats of acrylic ground unfortunately confusingly called acrylic gesso. Managing your WetCanvas! This topic has 4 replies, 3 voices, and was last updated 7 years, 4 months ago by bunford. Viewing 5 posts - 1 through 5 of 5 total. July 6, at am John Stirrips Default. Hi all. A lot of people chimed in and I found it very useful.
Thanks guys. Can any one clear this up for me?? It has been discussed earlier that impermeability reduced with the increasing value of surface water absorption. This characteristic was quite similar to the behavior exhibited by resistance to sulfate attack.
Based on Figure 11 , there was a linear correlation between surface water absorption and loss of compressive strength due to sulfate attack. In addition, loss of compressive strength showed a higher rate of decrement indicated by steep slopes of the curve. By contrast, the loss of compressive strength did not appear to depend upon internal water absorption, as shown in Figure 11 b.
The relationships between two parameters were calculated and their correlation results are presented in Figure 11 a. The rapid migration test provides value of , which is also under the assumption of constant chloride binding capacity during the test. Capillary absorption is an important mechanism related to the chloride ingress into concrete. Nonsaturated concrete in contact with a salt solution will absorb this solution by capillary forces [ 16 ].
Figure 12 gives the chloride ion diffusion coefficient of concrete. Figure 13 shows relationship between water absorption and chloride ion diffusion coefficient. Based on the results, it can be seen that chloride ion diffusion coefficient related to water absorption surface concrete, and chloride ion diffusion coefficient increased with the water absorption.
The sample with lowest absorption still showed the best resistance to chloride ion diffusion. Unlike previous results, chloride ion diffusion coefficient has exponent relation to water absorption, and the correlation coefficient is 0. The simultaneous action of diffusion and capillary suction thus causes a mixed transport mode. Once chloride penetrated, the initial mechanism appears to be suction when the surface is dry and chloride solution is rapidly absorbed by dry concrete.
Next, diffusion dominated transport mechanism, instead of capillary movement of chloride solution. Both of these two kinds of mechanism depended on pore structure, which was evaluated by water absorption here. Based on the results and the discussion of mechanical performance, permeability, sulfate attack, and chloride ion diffusion of the concrete with different water absorption, the following conclusions are drawn.
Curing conditions can greatly affect the water absorption of concrete. In addition, surface water absorption was higher than internal water absorption regardless of curing conditions. Both of surface water absorption and internal water absorption had no clear relationship with compressive strength, which indicated that the strength cannot be simply evaluated by water absorption. Permeability mainly depended on the surface water absorption of concrete, and there was a significant linear correlation between permeability and surface water absorption.
However, internal water absorption presented little relationships to permeability. Higher water absorption decreased resistance to sulfate attack of concrete, and the relationship between surface water absorption and resistance to sulfate attack was approximately linear.
Similarly, it presented a poor correlation between internal water absorption and resistance to sulfate attack. Furthermore, chloride ion diffusion coefficient has exponent relation to surface water absorption, and the correlation coefficient is 0.
As a whole, surface water absorption can be applied to predict some performance of concrete, including compressive strength, permeability, resistance to sulfate attack, and chloride ion diffusion. Zhang and L. This is an open access article distributed under the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Article of the Year Award: Outstanding research contributions of , as selected by our Chief Editors. Read the winning articles. Journal overview. Special Issues. Zhang 1 and L. Received 06 Jan Revised 18 Mar Accepted 18 Mar Published 10 Apr Abstract Environment has significant effects on the water absorption of concrete materials.
Introduction Durability of concrete plays a critical role in controlling its serviceability. Materials and Methods 2. Materials In experimental studies, the OPC Table 1. Table 2. Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. SEM photos of concrete samples: a condition b and b condition d. Figure 6. Figure 7. Relationship between water absorption and compressive strength: a surface water absorption and b internal water absorption.
Figure 8. Figure 9. Relationship between water absorption and permeability: a surface water absorption and b internal water absorption. Figure Relative strength of samples after sulfate attack. Relationship between water absorption and resistance to sulfate attack: a surface water absorption and b internal water absorption. Chloride ion diffusion coefficient of samples. Soil Testing. Garden Helpline. Ask Extension. Staff Directory. Permeable vs. Impermeable Surfaces What is the difference between permeable and impermeable surfaces?
What is the impact of impermeable surfaces on the environment? Urban and suburban sites typically contain large expanses of impermeable surface, causing a host of problems: Pollution of surface water.
When stormwater runs off impermeable surfaces, it picks up pollutants as it flows into storm drains. The contaminated water then flows directly into rivers, lakes, wetlands and oceans, generating problems for biodiversity as well as public health.
Flooding of surface water and erosion of stream banks. During periods of heavy rainfall, large amounts of impermeable surfaces generate large amounts of runoff.
This sudden influx of runoff into rivers can cause flash flooding and erosion of stream banks. Water table is not adequately recharged. Because impermeable surfaces send rainwater into storm drains rather than allow it to percolate down to our aquifers, groundwater may be used faster than it is recharged.
Formation of stagnate water puddles. On impermeable surfaces where runoff has no drainage route, stormwater can puddle for long periods of time. Stagnate puddles can become breeding places for undesirable insects such as mosquitoes. Heat island effect.
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