![\"Test](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2020\/02\/2020-02-05-11.04.51-1.jpg\")
<\/p>\nHello, everyone.<\/p>\n
This is Enta.<\/p>\n
Pollen is really getting to me lol<\/p>\n
But that's beside the point.<\/p>\n
<\/p>\n
Are you practicing for the exam?<\/p>\n
Even though the current format has been established for over 30 years now, what's the point of practice exams?<\/p>\n
That's what I end up thinking.<\/p>\n
Well, since the type and shape of sand (fine aggregate) vary by region, it affects the strength!<\/p>\n
I know that, though lol<\/p>\n
<\/p>\n
When it comes to sprayed mortar, you mix a 1:4 mortar ratio, and based on experience, it achieves the required strength nearly 99% of the time, right?<\/p>\n
When I write that, I\u2019m sure some of you will say, \u201cOh yeah, that\u2019s happened to me too\u2014I just couldn\u2019t bring myself to do it!\u201d<\/p>\n
<\/p>\n
I've had times when I couldn't get the strength either, lol.<\/p>\n
I tried to figure out why I didn't show up back then.<\/p>\n
1. Amount of Water<\/span><\/strong><\/span><\/p>\n 2. Incorrect formulation<\/span><\/strong><\/span><\/p>\n 3. Mixing Time<\/span><\/strong><\/span><\/p>\n 4. How to Remove the Core<\/span><\/strong><\/span><\/p>\n 5. Types of Sand<\/span><\/strong><\/span><\/p>\n 6. Temperature<\/span><\/strong><\/span><\/p>\n 7. Preparation of Test Specimens<\/span><\/strong><\/span><\/p>\n 8. The flatness of the test specimen is poor<\/span><\/strong><\/span><\/p>\n I guess those are the main causes, more or less.<\/p>\n <\/p>\n 1,<\/span><\/strong><\/span>Well, there\u2019s always at least a little chance of getting the amount of water wrong, right?<\/p>\n Sometimes craftsmen change the amount on their own to make it easier to blow. (Be careful when making test batches.)<\/p>\n However, even if the W\/C (water-to-cement ratio) changes slightly here, the concrete will still achieve the required strength.<\/p>\n <\/p>\n 2,<\/span><\/strong><\/span>There are no mistakes in the formula, lol. I think it's practically nonexistent.<\/p>\n Making a mistake here can be disastrous, so please study the basics from the beginning.<\/p>\n <\/p>\n 3,<\/span><\/strong>You don't need to worry too much about the mixing time.<\/p>\n It's hard to imagine that the lack of strength is due to this part being too short.<\/p>\n It's true that if it's quite short, mixing may not work properly, which can lead to inconsistencies.<\/p>\n However, since this is just a practice test, that seems unlikely.<\/p>\n <\/p>\n 4,<\/strong><\/span>Knowing how to remove the core is very important!<\/p>\n Actually, I think this might be the most important part.<\/p>\n A common mistake is removing the core even though it isn't strong enough.<\/p>\n For example, with ordinary cement, if you take a core sample on about the second day\u2014before the concrete has reached its one-week strength\u2014the cross-section (surface) will appear crumbly.<\/p>\n This is clearly a state in which no strength is being exerted.<\/p>\n This is not acceptable as a test specimen.<\/p>\n Since the \u03c650 portion of the \u03c650 \u00d7 100 mm section cannot be maintained and becomes narrower, the strength is reduced.<\/p>\n For regular cement, we recommend coring the day before or on the day of the job. (It\u2019s hard, though.)<\/p>\n It's reassuring when the surface is this smooth \u2191\u2191.<\/p>\n <\/p>\n 5,<\/span><\/strong><\/span>As for the type of sand, there are some types that don't hold up well.<\/p>\n Slope contractors definitely know this. (Local contractors)<\/p>\n \"They say sand from anywhere doesn't hold up, lol\"<\/p>\n In particular, sand that contains a lot of silt\u2014especially when it hasn\u2019t been washed thoroughly\u2014tends to have lower strength.<\/p>\n And it\u2019s better if the grain size is consistent\u2014neither too fine nor too coarse. (Some suppliers will blend it for you.)<\/p>\n <\/p>\n 6,<\/span><\/strong><\/span>Temperature is important.<\/p>\n Please be especially careful when pouring concrete in cold weather.<\/p>\n Under no circumstances should you add antifreeze at this time.<\/p>\n Since antifreeze inhibits the hydration reaction, it further slows down the hardening process.<\/p>\n Be careful\u2014there are a lot of false claims about antifreeze.<\/p>\n (As far as I know, the claim that there are two types of antifreeze was either a lie or a misunderstanding.)<\/p>\n (I've already tested this at an official testing facility, but since I can't make the results public, I'll show it to you privately lol)<\/p>\n I\u2019d actually like to try a few different experiments. (I\u2019ve already revealed all of them at the entertainment meetup, lol.)<\/p>\n <\/p>\n 7,<\/span><\/strong><\/span>Since the test specimens were spray-applied, I don't think there will be any particular issues.<\/p>\n However, please be careful, as there are rare instances when you end up chewing nothing but\u30ed\u30b9, resulting in a mille-feuille of\u30ed\u30b9 and mortar.<\/p>\n After I made it, I just left it there to make sure the conditions matched those on site, lol.<\/p>\n <\/p>\n 8,<\/span><\/strong><\/span>Do you flat-grind the test specimens before conducting compressive strength tests?<\/p>\n This is extremely important\u2014if the surface isn't flat, uneven stress will be applied, making it difficult to achieve the required strength!<\/p>\n If it's a core, we definitely recommend polishing both sides.<\/p>\n <\/p>\n That's the general idea.<\/p>\n I'm sure there are plenty of others as well.<\/p>\n External factors, such as capping at the strength testing facility, may also have an impact.<\/p>\n I think the person who did it knows best where they went wrong.<\/p>\n If I'm going to do it anyway, I might as well prepare for the exam perfectly, lol.<\/p>\n <\/p>\n See you later.<\/p>","protected":false},"excerpt":{"rendered":" Hello, everyone. This is Enta. I\u2019m getting hammered by pollen, lol. But anyway, are you practicing for the exam? Even though the current format has been established for over 30 years now, I can\u2019t help but wonder, \u201cWhat\u2019s the point of practicing for the exam?\u201d Well, depending on the region, the type of sand (fine aggregate)\u2026<\/p>","protected":false},"author":2,"featured_media":41138,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[38],"tags":[107,291,292,435,876,1965],"class_list":["post-50968","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-construction-management","tag-107","tag-291","tag-292","tag-435","tag-876","tag-1965"],"acf":[],"yoast_head":"\n![\"Core\"](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2020\/02\/2020-02-08-08.47.34.jpg\")
<\/p>\n![\"Mortar](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2017\/03\/c7179b320afc9c18844303695b52b2da-e1581124554312.jpg\")
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