readx; The road repair mentioned by Zhu Youzhen is not as simple as maintaining the existing official roads. Pen "Fun" Pavilion www.biquge.info [.. As soon as he made a move, he made a big move, and while keeping the existing official roads open, a new highway from Beijing to Shanhaiguan broke ground.

Building a high-standard and modern road has always been Zhu Youzhen's dream since he crossed over. The reason is also simple: the roads of this era are too rudimentary. Needless to say, country roads, even official roads, which are responsible for connecting the rest of the country, are all dirt roads. The defects of dirt roads are obvious, with poor wear resistance, especially fear of rain, and potholes over time.

Take the official road from Jingshi to Tongzhou as an example, it has a history of more than 200 years since it was built in the Hongwu period. Although it has been repaired repeatedly, with the crushing of vehicles and the washing of rainwater, the road surface has sunk severely, and it looks like a trench at first glance. On a sunny day, vehicles can still pass slowly along deep ruts; When it rains, it simply becomes a river, and it can only be restored after the stagnant water evaporates and seeps, and its inefficiency can be imagined.

The official road in other places is relatively poor, but the official road from Jingshi to Shanhaiguan is responsible for transporting grain and materials to the eastern Liaodong region, and the road surface is too poor, which has had a great negative impact on the fight against the Manchu Qing Dynasty.

For example, the straight-line distance between the two places is only more than 500 li, and there are mostly plains along the way, so it stands to reason that the cavalry can arrive in two or three days, and the infantry can travel 50 li a day every day, and they should arrive in 10 days.

However, the movement of the army is not only men and horses, but more importantly, grain and grass, which are naturally pulled by carts. On such a dilapidated official road, it would be good for the baggage vehicles to walk twenty miles a day, like a few years ago when Zhu Youzhen went out on behalf of the Son of Heaven, and tens of thousands of troops arrived at Shanhaiguan for twenty days, and the baggage vehicles were late, but the battle of Ningyuan was already over, and those baggage did not play a role at all.

This is only more than 500 miles, and if you travel from Jiangnan or even Lingnan to the north, the journey will be two or three thousand miles, and it will take several months to transport large quantities of materials. On the way to transportation, the person in charge of transportation also has to eat, and when the grain is transported to the destination, they often eat half of it.

Moreover, there were no cars in this era, except for the Beijing-Hangzhou Grand Canal, which basically relied on animal power. The mule pulls the cart, the wooden wheels skeleting in deep ruts, and if you think about it, you can't be fast. Even if the car is empty, the driver has to control the speed of the animals, otherwise once he runs desperately, he can't run far, and the car will fall apart.

Therefore, Zhu Youzhen has long wanted to rebuild the official road from Jingshi to Shanhaiguan. Now that the battle to defend the capital has ended, Amin's inlaid white flag has already been within his calculations, and it will not take long to completely solve it, and it is impossible for the Manchu army to enter the pass again in the short term, and it is a good time to build roads. The reason why so many workers are recruited is to give full play to the advantages of a large number of people, complete the construction of this road in a hurry, and put it into use as soon as possible.

But this time, Zhu Youzhen doesn't plan to build a masonry road similar to the one he did in Jingyang County, he wants to build an asphalt road!

Before the road was built, Zhu Youzhen also arranged a major event, that is, the Ministry of Industry took the lead in opening a steel-making plant and a coking plant in the southeast corner of the outer city of Beijing, close to the Tonghui River, which was personally presided over by Xu Guangqi, the secretary of the Ministry of Industry. Construction of the steel mill has not yet begun, but the coking plant has already started production.

In this era, of course, the soil method of coking was carried out, which simply means that a large amount of pulverized coal was piled up in a coke oven made of adobe, and then manually ignited with the help of the ignition holes on the side wall, and the coal was made into coke by the heat generated by the combustion of the coal itself. Coke is an important fuel used in iron smelting, it has a higher calorific value than charcoal, without coke, the furnace temperature can not reach a sufficient height, and the quality of smelted pig iron will be greatly reduced.

And in the process of coking, there is also a by-product, which is coal tar. Coal tar, commonly known as coal paste, is a black-brown viscous liquid produced during the coking process. In the past, when artisans made coking, they threw away coal tar as waste, which was not only wasteful, but also polluted the environment.

However, Zhu Youzhen knew with common sense that coal tar could be distilled to obtain coal tar pitch. As for the other uses of coal tar, Zhu Youzhen didn't know about it, but just getting asphalt was enough for him to build a factory, because asphalt is an important material for modern road paving!

In fact, the main thing used in modern paving is petroleum asphalt, and coal tar asphalt contains a variety of harmful components to the human body, and it is not resistant to high temperatures, easy to soften, and belongs to the things that need to be eliminated. But in this time and space, oil has not been exploited on a large scale, and naturally there is no petroleum asphalt, so Zhu Youjian can only retreat.

As long as asphalt can be made, the rest is easy. When Zhu Youzhen was a child, he didn't see workers "frying oil" on the road, simply put, mixing heated asphalt with concrete, small stones and other things, and then laying it on the roadbed while it was hot and rolling it flat with a road roller. When this layer of mixture cools, a hard and smooth pavement is formed. There is no concrete yet, but it can be used by mixing sand, gravel and asphalt, and it can be used after artisan testing, but it is not stronger.

As for the rollers, of course, Zhu Youzhen couldn't have come up with such a thing, but the craftsmen quickly came up with an alternative. That is, the pavement is divided into small pieces with wooden boards, and when asphalt is paved, one by one, and then immediately flattened with flat planks, and the gaps between the small pieces are later "patched". Although the manpower is far worse than the roller, it is impossible to press so tightly, but it can also be used improvised, and the flatness can fully meet the needs.

Of course, coal tar is a by-product of coking, and the yield is very low, and even less asphalt is obtained. With the existing scale of coking, only a dozen zhang of road can be paved every day. And "frying oil" needs to be done in one go, so the main content of construction at this stage is to build a roadbed.

This is simple, mainly to mine the earth and tamp it layer by layer. The newly recruited 20,000 workers, plus some of the workers who built the outer city of Jingshi before, tens of thousands of people started work at the same time, isn't that fast? Moreover, in the process of construction, effective methods such as sectional operation and remuneration according to the workload have also been adopted, and the workers are also motivated to work, but they do not work without effort like in the past.

Gu Yanwu, as a Tongzhou colleague, naturally has to inspect this major project every day. But one day he was surprised to find that dozens of workers were also working on the north side of the new highway construction site, and a short section of rammed earth roadbed had been built. But they scattered a lot of stones on the roadbed, and they didn't know what to do.

When he walked up, Gu Yanwu suddenly found that one of these dozens of people was his old acquaintance, and he couldn't help but exclaim in surprise: "Brother Chang Geng, why are you here?!" ”

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