Besi Beton tentu bukan istilah yang asing lagi di telinga kita? Namun walaupun sering mendengarnya, seringkali kita tidak bisa menjelaskan dengan baik pengertian dari istilah besi beton tersebut.

Besi beton berbeda dengan besi – besi biasa. Besi beton adalah besi yang biasa digunakan untuk penulangan dalam konstruksi beton atau yang biasa dikenal dengan sebutan beton bertulang. Besi beton ini telah memiliki peran yang sangat penting dalam sebuah konstruksi. Beton pada prinsipnya telah mempunyai kekuatan yang terbatas untuk memikul beban. Oleh sebab itu, penulangan pada beton biasanya ditambah dengan beso beton agar konstruksinya menjadi lebih kuat dan akhirnya dapat memikul beban – beban atau gaya yang bekerja sehingga dikenal istilah beton bertulang.

Munculnya istilah beton bertulang karena terdiri dari dua material dalam instrumen pembuatannya yaitu beton dan besi tulangan. Fungsi tulangan dalam beton bertulang adalah untuk dapat menahan gaya atau tegangan tarik yang bekerja pada konstruksi.

Besi beton telah terdiri dari dua macam yaitu besi ulir dan besi dengan bentuk polos. Pada besi bentuk polos, bentuk penampangnya tidak bersirip, permukaannya lincin, dan berbentuk bundar. Sedangkan untuk jenis besi ulir identik dengan bentuk bersirip yang memanjang dengan pola tertentu. Pola tersebut bisa bermacam – macam, bisa sesuai dengan pilihan pola pada proses pembuatannya.

Besi beton sebenarnya bukan hal yang baru lagi dalam dunia konstruksi karena besi beton sudah digunakan sejak tahun 1950 sebagai elemen utama untuk pembangunan gedung – gedung tinggi. Pada awal abad ke-20, banyak gedung – gedung tinggi di Amerika yang menggunakan baja profil dalam struktur utamanya. Pada tahun 50an, konstruksi beton baru mulai ikut ambil bagian dalam konstruksi gedung tinggi.

Sementara itu, di Indonesia sendiri, besi beton biasa digunakan sebagai inti untuk pembangunan gedung karena besi beton lebih mudah didapat dan lebih ekonomis daripada konstruksi lainnya. Saat ini besi beton merupakan bahan yang paling penting dalam konstruksi karena digunakan dalam berbagai macam bentuk misalnya untuk jembatan, drainase, dinding penahan tanah, bendungan, bangunan, dll.

From sea to shining sea, or at least from one side of the Hudson to the other, politicians you have barely heard of are being accused of wrongdoing. There were so many court proceedings involving public officials on Monday that it was hard to keep up.

In Newark, two underlings of Gov. Chris Christie were arraigned on charges that they were in on the truly deranged plot to block traffic leading onto the George Washington Bridge.

Ten miles away, in Lower Manhattan, Dean G. Skelos, the leader of the New York State Senate, and his son, Adam B. Skelos, were arrested by the Federal Bureau of Investigation on accusations of far more conventional political larceny, involving a job with a sewer company for the son and commissions on title insurance and bond work.

The younger man managed to receive a 150 percent pay increase from the sewer company even though, as he said on tape, he “literally knew nothing about water or, you know, any of that stuff,” according to a criminal complaint the United States attorney’s office filed.

The success of Adam Skelos, 32, was attributed by prosecutors to his father’s influence as the leader of the Senate and as a potentate among state Republicans. The indictment can also be read as one of those unfailingly sad tales of a father who cannot stop indulging a grown son. The senator himself is not alleged to have profited from the schemes, except by being relieved of the burden of underwriting Adam.

The bridge traffic caper is its own species of crazy; what distinguishes the charges against the two Skeloses is the apparent absence of a survival instinct. It is one thing not to know anything about water or that stuff. More remarkable, if true, is the fact that the sewer machinations continued even after the former New York Assembly speaker, Sheldon Silver, was charged in January with taking bribes disguised as fees.

It was by then common gossip in political and news media circles that Senator Skelos, a Republican, the counterpart in the Senate to Mr. Silver, a Democrat, in the Assembly, could be next in line for the criminal dock. “Stay tuned,” the United States attorney, Preet Bharara said, leaving not much to the imagination.

Even though the cat had been unmistakably belled, Skelos father and son continued to talk about how to advance the interests of the sewer company, though the son did begin to use a burner cellphone, the kind people pay for in cash, with no traceable contracts.

That was indeed prudent, as prosecutors had been wiretapping the cellphones of both men. But it would seem that the burner was of limited value, because by then the prosecutors had managed to secure the help of a business executive who agreed to record calls with the Skeloses. It would further seem that the business executive was more attentive to the perils of pending investigations than the politician.

Through the end of the New York State budget negotiations in March, the hopes of the younger Skelos rested on his father’s ability to devise legislation that would benefit the sewer company. That did not pan out. But Senator Skelos did boast that he had haggled with Gov. Andrew M. Cuomo, a Democrat, in a successful effort to raise a $150 million allocation for Long Island to $550 million, for what the budget called “transformative economic development projects.” It included money for the kind of work done by the sewer company.

The lawyer for Adam Skelos said he was not guilty and would win in court. Senator Skelos issued a ringing declaration that he was unequivocally innocent.

THIS was also the approach taken in New Jersey by Bill Baroni, a man of great presence and eloquence who stopped outside the federal courthouse to note that he had taken risks as a Republican by bucking his party to support paid family leave, medical marijuana and marriage equality. “I would never risk my career, my job, my reputation for something like this,” Mr. Baroni said. “I am an innocent man.”

The lawyer for his co-defendant, Bridget Anne Kelly, the former deputy chief of staff to Mr. Christie, a Republican, said that she would strongly rebut the charges.

Perhaps they had nothing to do with the lane closings. But neither Mr. Baroni nor Ms. Kelly addressed the question of why they did not return repeated calls from the mayor of Fort Lee, N.J., begging them to stop the traffic tie-ups, over three days.

That silence was a low moment. But perhaps New York hit bottom faster. Senator Skelos, the prosecutors charged, arranged to meet Long Island politicians at the wake of Wenjian Liu, a New York City police officer shot dead in December, to press for payments to the company employing his son.

Sometimes it seems as though for some people, the only thing to be ashamed of is shame itself.